81. THE RACE FOR AUTONOMOUS ELECTRIC VEHICLES                             

The California Department of Motor Vehicles (DMV) proposed today a new set of rules that will govern the operation of autonomous vehicles on the state's roads. Simultaneously, Google announced that it was spinning off its self-driving car unit into a standalone business setting up the stage for a fleet of self-driving taxis that will compete head-to-head with Uber, which itself is investing heavily in self-driving vehicles. Tesla, GM, Mercedes Benz, Ford and several others have not been shy in the media, all announcing efforts and prototypes towards autonomous driving. 

The Google (or perhaps more aptly under its new name of Alphabet) pod-like self-driving vehicles are powered by batteries, so it is fair to say that it is only a matter of time before electric powertrains  become the foundation for this new vision of autonomous cars. The race is early, still very early, but the stakes are potentially immense. 

One of the early metrics of a race worth gauging is each player's present IP position. It is not a simple question to answer but one can glean some insight -- autonomous electric vehicles are very sophisticated systems using complex components, so one would expect that intellectual property will play a central role both in the development of this market segment as well as eventual litigation among the participants.

The next two charts show the extent of the present IP position for a select number of companies. The chart on the left shows the number of US patents issued since 2000 covering two categories: i) battery technology including battery battery materials, manufacturing and battery management systems, and ii) technologies related to designing and building electric vehicles. For the time being, I will focus this post on the "electric" portion of this race, addressing the battery and electric systems for these vehicles -- leaving autonomous driving for others to discuss. I assume that the number of issued US patents will reflect within reason the amount of know-how a company possesses in battery and EV technologies. 

The first observation that stands out is the large number of US patents that Toyota has secured in both areas of batteries and electric vehicle systems. They eclipse the number of patents issued to Tesla and GM. Honda and Ford, two companies that have been relatively quiet in the media, are clearly building their foundations. The German automakers, judging from their US patent portfolio, seem to be lagging -- though this should not be misinterpreted as losing or lagging in the race. Apple has not yet publicly announced that it plans to build cars, but rumors abound in this respect and as such, the companies is categorized with the automakers. Their portfolio, however, is heavily biased towards battery technology, courtesy of their prowess in consumer devices. 

Automakers rely heavily on suppliers of components and subsystems. Among the well-established ones, Robert Bosch stands out with a sizable bag of issued US patents covering both batteries and electrical vehicles. Samsung and LG, two large suppliers of electronic components to the Korean car makers, have a strong IP position in building batteries owing to their respective battery divisions, SDI and LG Chem -- but there is not much evidence of strong IP in electrical powertrain and electric vehicles. It is also surprising to see Delphi and Johnson Controls lagging in both categories -- could this mean that the automakers are choosing to own and control key technologies instead of outsourcing them to their traditional supply chain partners? Time will tell. 

In this evolving race and ambitious vision for the future, these statistics are merely just perturbations for the time being. However, given enough time, they could amplify and influence the outcome of who will win and who will not. Stay tuned!

© Qnovo, Inc. 2015 / @QNOVOcorp @nadimmaluf #QNOVOCorp    http://www.qnovo.com

79. CAN I FAST-CHARGE MY TESLA OR EV?                                                     

Before I start this post, I encourage all new readers to go back to the early posts if they desire to learn more about the basics of lithium-ion batteries and their operation.

This post is dedicated to deciphering the growing complexity of charging stations for plug-in hybrid and pure electric vehicles (xEVs), especially as their popularity grows among drivers. 

The charging of xEVs, whether at your home or at dedicated charging stations, is usually governed by a set of standards agreed upon by a vast number of contributing organizations, such as the automakers, electric utilities, component makers and many others. Several organizations including SAE International, ANSI and IEEE have led the  coordination and development of such standards -- they are numerous -- covering, for instance, the types and interoperability of connector designs and charging power levels (SAE J1772), communication and signaling protocols  (SAE J2931/1) between the xEV and the charging station (also known as EV supply equipment -- EVSE), wireless charging (SAE J2954) as well as many others related to diagnostics, safety, DC charging...etc. Today's post addresses charging from the perspective of the SAE J1772 standard and its competing standard CHAdeMO.

So let's start with understanding what charging levels are and how they are defined by the various standards. There are 4 levels of charging:  two levels using conventional AC charging, and two additional levels using higher-voltage DC  charging. They are summarized in the next table:

Let's start with AC levels 1 and 2. Level 1 is what you get using the charging cord supplied to you by the car maker if you own an xEV. It plugs into the standard 120V household outlet and delivers, in theory 1.7kW. Some of you are probably tempted to multiply 120V by 20A and realize that's more than 1.7kW...if you are that person, remember that this is an AC current, so you need to multiply by 0.707. This is the maximum power delivered to the connector plugged into the car. It is not the power delivered to the battery. The battery's power is delivered by an on-board battery management system (on-board charger) that has to convert the voltage to a level appropriate for the battery. In reality, the car battery receives a best-case power of about 1.2 - 1.3kW to account for the electrical efficiency of the system -- taking an average consumption of 250Wh per mile, that is equivalent to about 5 to 6 miles for each hour of charging...ouch!

Reality is a little worse than that: standard household power plugs are limited to 15A (instead of 20A) thereby decreasing the power delivered to the battery to a measly 900W. At this power level, a Nissan Leaf's battery (nominal 24kWh / effective 20kWh) takes 22 hours to fully charge. Yikes! Now one can begin to understand why xEV owners do not line up near a Level 1 charger...but it does get crowded at a Level 2 charger.

AC Level 2 uses a 240V single-phase mains. The lowest current level is 20A corresponding to a maximum power (again at the output of the connector) of 3.4kW. The typical public charging stations, such as the ones managed by ChargePoint, provide 6.7kW. However, there is a catch. The on-board charging circuitry in your xEV must be able to use that power. Early Nissan Leaf models had 3.3kW-circuitry -- in other words, regardless of the maximum power at the charging station, the maximum power the car is willing to accept is 3.3kW.  Newer xEV models, e.g., Nissan Leaf, Ford Focus Electric, Chevy Volt, have on-board chargers capable of up to 6.6kW. Again, this means if the charging station were to provide 19.2kW, your car cannot accept more than 6.6kW...this is by far the most common charging level as dictated by the presently deployed infrastructure. It equates to about 25 miles for each hour of charging. Once again, using the Nissan Leaf as an example, its battery will fully charge in 3.5 hours with a Level 2 charger (6.6kW). That's not fast charging, but it sure is a heck-of-a-lot faster than Level 1.

Fast charging with DC gets more complex because there are competing approaches. Of course, we are also now talking about insanely high power levels, and consequently very expensive charging stations  and associated installation costs ($50,000 to $100,000 each).

SAE has the J1772 Combo DC standard. CHAdeMO has another competing standard. Tesla has its own proprietary fast-charging using their network of Superchargers (though not DC). But what they have in common is that they all seek to provide high power levels to the vehicle...up to 120kW. This infrastructure is still relatively scarce -- Tesla is the only one aggressively deploying fast charging Superchargers along specially designated highway corridors.

Naturally, charging a car battery at such high power levels begs a new series of questions on whether this creates any significant and permanent damage to the battery. The brief answer is: YES, damage does occur...but super fast charging is so rare that no one is really paying attention to this question, at least not for now. Besides, with the exception of Tesla, your average xEV cannot charge faster than 6.7kW, so having a fast charging station is a moot point. 

A final word on fast charging the Tesla batteries. At 120kW of input power, this equates to a charging rate of 120/85 = 1.4C -- this is guaranteed to cause serious damage to your Tesla battery if you were to charge on a regular basis. But then again, if Elon Musk and Tesla Motors are willing to cover you under their warranty, do you really care?

© Qnovo, Inc. 2015 / @QNOVOcorp @nadimmaluf #QNOVOCorp    http://www.qnovo.com

77. THE FINANCIAL DILEMMA OF BATTERY MANUFACTURERS                           

The lithium-ion battery market is large. For consumer devices, it will exceed $10B in 2015 corresponding to a total output capacity of 40 GWh. The promise of even greater markets in stationary energy storage and electric vehicles is attracting interest and investment. Goldman Sachs estimates that the energy storage market could reach a demand greater than 700 GWh in 2015, eclipsing the expected 175 GWh capacity demand for electric vehicles.

But these large market figures belie the harsh market realities of building batteries, in particular manufacturing cells for lithium-ion applications. This post will dive a little deeper into the financial challenges that cell manufacturers are facing today and will most likely face as the battery markets expand rapidly in the coming years.

Let's start by looking at the present state of cell manufacturers. The bulk of the manufactured cells goes to fulfill the demand in consumer devices, including some 1.4B smartphones and 400+ million laptops and tablets. To first order, 4 major cell suppliers deliver 80% or more of these cells, mostly polymer cells. 

The $10 Billion-battery consumer market is serviced primarily by 4 large Asia-based suppliers.

By virtue of the market size and volume, batteries for consumer devices have been and continue to be under immense pricing pressures. On average, the pricing is about $0.25 per Wh, but that can be as low as $0.10 per Wh for some of the vintage low energy density batteries. This competitive landscape left these battery suppliers with, let's just say, less-than-attractive financial statements. For example, a visit to LG Chem's website reveals the financial situation for their "energy division." For this most recent 3rd quarter in 2015, it recorded revenues of approximately $640m, about 80-85% of it from consumer devices, and the rest from their sale into xEVs (Electric and hybrid electric vehicles). Against these revenues, the company recorded a meager profit of 1.3%. It had reported a 6% loss in the prior quarter. Gross margins for battery manufacturers tend to be in the range of 10 - 20% at best. That's nothing to write home about.

Such strained financials seldom give the company's management any latitude to invest in extensive R&D -- the expectation of future returns on invested R&D is often missing in such scenarios. The result is diminishing innovation, rising pricing pressures, and the onslaught -- more rapid than one might imagine -- of new low-cost manufacturers, especially ones based in China. 

Instead, the management teams of battery manufacturing companies begin to look at alternative markets that can be financially more rewarding. After all, they are all watching Panasonic reap the rewards of their relationship with Tesla. Panasonic recorded nearly $800m of sales to Tesla in 2014, and the markets expect the number will grow to $3.35B in 2020 if and when Tesla succeeds in shipping 250,000 electric vehicles. 

We can witness this change of direction from a number of observations. First, Nikkei published on 28 October a report that Tesla is in discussions to source batteries from LG Chem, in addition to Panasonic. Second, let's take a look at Samsung SDI's revenue projections for their battery division.

One can immediately see flat revenues from their mobile product line, but growing projected sales from energy storage as well as transportation. In other words, the unstated strategy of these giant conglomerates is to controllably relinquish their mobile market share to their Chinese competitors and focus on winning in the growing but hopefully more profitable storage and xEV markets. In these markets, there is also room for them to add value beyond building cells -- they can also build packs and the complex battery management systems.

So where does this leave innovation in consumer devices? most likely stranded! Increasing pricing pressures from Chinese manufacturers makes it quite unattractive to invest in consumer batteries -- thus leaving the mobile device OEMs at the mercy of decreasing cell quality and possibly performance.  Of course, I am sure someone will argue why can't the innovation trickle down from energy storage and xEVs to consumer? The answer is that these are complex systems where innovation is often at the system-level and less so at the cell-level where consumer devices demand it. Additionally, the cost points for these large-scale systems are vastly different from the relatively simpler consumer device; hence the dilemma that is creeping up rapidly on both battery manufacturers and consumer device OEMs. This is also the commoditization of the lithium-ion battery.

© Qnovo, Inc. 2015 / @QNOVOcorp @nadimmaluf #QNOVOCorp    http://www.qnovo.com

72. LET'S TALK ABOUT THE WAIST                                                               

Not yours, of course....the smartphone's waist. We see a race among the smartphone makers to go thin. The iPhone 6 Plus is 6.9 mm thick and it is already been outflanked by some new devices coming from China. In particular, the Oppo R5 boasts a thickness of only 4.85 mm, and the Vivo X5 Max is an even thinner 4.75 mm. So what determines how thin one can go?

Naturally, the mechanics of the device are clearly one limiting factor...nobody wants their smartphone to "bend." For the most part, manufacturers are now using hardened aluminum cases for added resistance to bending. With the exception of some early complaints about the iPhone 6 Plus, there have been no credible reports of additional bending failures. Another limiting factor is the touch screen. There have been some great innovation here, most of it related to fusing the touch glass with the display, thereby reducing the touchscreen thickness. For example, the AMOLED screen on the Vivo X5 Max is only 1.35 mm thick.

So that leaves the battery as the last frontier...why am I not surprised? The battery seems to consistently win the title of bottleneck, and this is the topic of today's discussion. Why can't we make batteries ultra thin?

The answer is actually "yes, we can." Batteries can be made really thin, I mean thinner than you might imagine, sub 1 mm. But naturally, there are tradeoffs. The first tradeoff is that thinner batteries cannot boast the same energy density than their thicker counterparts -- there is just too much "electrical overhead" (e.g., connectors, plates) that they become dominant when the battery is too thin. See this earlier post that shows the impact of thickness on energy density. For a smartphone device, somewhere around 3 mm is the lower limit of battery thickness. Some smartphone makers instead choose to go thick just to provide more battery capacity -- the most recent example is the Moto X whose thickness is a whopping 11 mm, more than double Oppo's thickness !!!! So the first tradeoff is battery capacity vs. stylishness. Judging from the market trends, stylishness seems to be winning for now.

There is also a second and very important tradeoff, and that relates to swelling. I described in a very early post what happens to the battery as it ages...it bloats, and consequently becomes unsafe. This "swelling" phenomenon, through which the battery physically grows, has two components. They are shown in the next chart.

This chart shows the actual and measured thickness of a 3-Ah cell used in the LG G2 smartphone. It is a polymer cell and is embedded (i.e., non-removable) inside the mobile device. The thickness is measured over 60 cycles of charging and discharging. One readily observes two separate trends, almost like a yoyo on an escalator:

• One trend is a fast variation in thickness with a known periodicity of one cycle (this is the yoyo effect). The thickness varies by about 0.15 mm, or approximately 3% of the cell's thickness but is a fully reversible effect. This is due to the physical expansion of the graphite anode. During charging, lithium ions intercalate (fancy language for "insert themselves") inside the carbon-graphite material (also known as matrix) thereby pushing the carbon atoms aside and causing physical growth. During discharge, the opposite happens and the anode returns to a thinner state.

• The second trend is a slow, semi-linear growth in thickness (this is the escalator effect). This is related to irreversible damage to the graphite anode -- as the lithium ions go in and out of the anode, they leave just a tiny bit of damage that accumulates over time into this irreversible thickening of the anode (and consequently of the cell). As one can immediately observe, this second trend is significantly larger in magnitude than the first trend. For this cell made by LG Chem, the increase in thickness over 60 cycles is 0.15 mm, or 3% of the original thickness. Typically, over 500 cycles, this may reach 8 or even 10%.

As a result, manufacturers of smartphones need to make an allowance inside the device for the battery cell to grow in time -- this allowance is somewhere between 10 and 15% of the cell's thickness, or up to 0.7 mm; quite a significant number. Failing to provide this allowance risks placing large pressures on the touchscreen and cracking it.

© Qnovo, Inc. 2015 / @QNOVOcorp @nadimmaluf #QNOVOCorp    http://www.qnovo.com

70.  REVIVING A DEAD BATTERY, REALLY?                                                                 

A statement of this devilish nature during the middle ages would have earned its author a burning at the stake. The mere notion of a "battery" would have probably been in the realm of druids and witches, and reviving anything dead would have been...well, enough said, it is the 21st century.

I will digress today a little and talk about your average primary (i.e., non-rechargeable) battery, the type that Energizer, Duracell, and their competitors sell billions of every year, all of which wind up in the trash bin or recycling centers -- excepting the batteries that sit on one's desk for ages as if somehow they will disappear on their own. How do these batteries die, and when they do, are they really dead? Let's explore.

For the purpose of this discussion, let's focus on Alkaline batteries. The typical ones, like AA or AAA, are nominally rated at 1.5 V. In other words, when they are fresh and unused, one would measure 1.5 V at the battery terminals. As the battery is inserted into a gadget and gets used, the voltage at the terminals drops, and fast it does. As the voltage drops, it reaches a point where it is no longer sufficient to power the electronics in the gadget. Often, these gadgets, such as toys, employ inexpensive electronics. This means that these electronics do not employ the most modern electronics circuitry. This is parlance for electronics that are not low-voltage and low-power. In other words, these inexpensive electronics draw more current than they need to, and they operate at higher voltages than they should -- all in the spirit of saving costs. But these operating requirements place a bigger burden on the battery, the result of which the battery's voltage drains rapidly and meets an early death.

It should be apparent to the reader that the end of the battery -- its "death" --  is now defined as the time at which its terminal voltage is no longer able to power the electronics. This is somewhat subjective because that clearly depends on the quality and sophistication of the electronics in your gadget. Usually, many inexpensive electronics begin to stop operating somewhere between 1.2 V and 1.35 V. Very rarely, one may see electronics get lower in operating voltages but such gadgets would most likely be associated with higher price points, and could very well just use an embedded lithium-ion battery to project an image of a "good" product.

Looking at the Energizer E91 specification sheet, one immediately can observe that this battery has a life of less than 2 hours to hit 1.3 V, and 3 hours to hit 1.2 V (assuming a discharge current of 250 mA). At this point, the electronics begin to stop operating; the cheap display on your child's toy begins to fade, and voila, you pronounce the battery dead and discard it.

But wait! Is it really true that the battery is dead? Again, it is a matter of definition. For a helpless parent trying to appease a screaming child, the battery is DEAD. But to some engineers and entrepreneurs, they will be quick to observe that this battery continues to hold a lot of charge and energy. Looking at the voltage chart above for the E91, the area under the red curve is the amount of "energy" that the battery holds. So it becomes immediately clear that if the battery is declared dead at 1.2 V, it continues to hold about 75% of its original energy. This is a lot!

So the magic question becomes how to access this extra energy well? and how to do so in a cost-effective and reliable manner? This is where I will put a plug for the company Batteroo Inc.. The team figured out an elegant solution to put a very thin reusable sleeve around the presumed dead battery with low-power electronics that will "boost and regulate" the raw terminal voltage of the battery back up to a higher voltage, say 1.5 V, sufficient now to operate a gadget. This has an effect of reviving this "dead" battery and substantially extending its life. I love clever and simple ideas! Batteroo's challenge is now to fight off the battery vendors who will not be pleased with selling fewer batteries.

© Qnovo, Inc. 2015 / @QNOVOcorp @nadimmaluf #QNOVOCorp    http://www.qnovo.com

68. AND THE MAGIC NUMBER IS 3K                                                                  

That is 3,000 mAh....this is the battery capacity that consumers will see in most mid-tier to high-end mobile smartphones for the foreseeable future. Why? It's simple, this is the capacity that gives consumers an honest full day of operation. 

This begs a first question: what is an honest full day? no one really knows since usage varies considerably across the consumer base. But manufacturers are not able to tailor the battery to different consumer groups, therefore, an honest full day of operation ought to fulfill the demands of the largest cross section of consumers, including the spectrum from travelers to stay-home parents and teenagers who are glued to their favorite social network app. It would be fair to say that an honest full day ought to deliver at least 10 hours of talk time per day, preferably more, and at least 10 hours of screen usage time, including web browsing and app usage.

The two charts below examine talk time and web browsing time for a number of commonly available smartphones as measured by GSM Arena in their battery tests. For talk time, the relationship is immediately obvious. More battery capacity equals more talk time. Simple and easy.  Some smartphone makers are a little better than others, but overall, there is a simple relationship that says that about 3,000 mAh gives about 20 hours of 3G talk time. Now these are lab-based tests, so in real life, you would want to give yourself a little extra margin.  But I would say that 3,000 mAh is probably sufficient for most phone-talking needs, most likely lasting you several days if all you do is only using your smartphone to talk. 

Now, talking on the phone does not need the screen to be turned on, but everything else, from simple messaging to browsing and app usage does. The screen is a major power hog as I explained in a previous blog. This is where the battery begins to get challenged. The next chart shows measured usage time for web browsing, a good proxy for having the display as well as the radios turned on.

The picture now gets a little more involved. Clearly a bigger battery equals more time, but also the choice of smartphone does matter. For example, Apple and Sony seem to do a better job managing the power budget than HTC and LG do. Nonetheless, the chart is also specific in saying that if you are gunning for about 10 hours or more of screen time per day on a device that has a 5-in display, then the battery capacity needs to be right around 3,000 mAh (or more).

So there you have it....anything less than 3,000 mAh will leave consumers unhappy with their battery performance. Anything much more than 3,000 mAh will leave the manufacturer with a more expensive battery that will not likely earn this manufacturer any additional sales. So it seems that 3,000 mAh will be the right figure for a little while.

Now let's find the approximate charge times for such a battery. Such a battery has an equivalent energy of about 11.5 Wh. So a standard 5-Watt AC adapter will charge this battery at nearly 0.4C (=5/11.5) for which the charge time is an agonizing 3+ hours (see my earlier post on charge times). New AC adapters capable of charging at 12-18 Watts will accelerate the charge times. In other words,  such larger batteries will undoubtedly go hand-in-hand with fast charging...and that's what consumers will want to see in their mobile smartphones soon: a full-day battery that can be charge in the fastest possible time. Expect such new crops of smartphones to emerge in 2016.

© Qnovo, Inc. 2015 / @QNOVOcorp @nadimmaluf #QNOVOCorp    http://www.qnovo.com

65. ON THE EFFICIENCY OF BATTERY-POWERED VEHICLES                        

Fact: I am able to ride a significantly longer distance on my bicycle than I can drive in my electric vehicle....it can be frustrating to see my electric vehicle run out of juice! So I began to wonder on a recent cycling trip to what extent my Ford Focus Electric vehicle was less  energy efficient than my bicycle? or perhaps was my electric vehicle not well designed and the battery appropriately sized? It was time to dig a little deeper.

Curiosity meant that I had to take the thought one step further: how would these two transportation modes compare with nature-provided bipedalism, and ultimately, with the modern gasoline-powered automobile. This is most likely a purely academic exercise in the sense that none of these transportation modes is meant to replace the other, at least not today, but is meant with the hope that we can learn from one method to improve our design and engineering methodologies.

So let's start by measuring an estimate of energy consumption for each of these transportation modes. First, I know from the dashboard of my electric vehicle that I have averaged 235 Watt-hours per mile (Wh/mi) over the past 20,000 miles of driving.  I also know from my bicycle instrumentation that I am averaging approximately 50 kCal per mile -- granted, that is at a faster pace than most casual riders but still represents a good starting number. We also know that a medium-sized gasoline-powered sedan has an average fuel economy of approximately 25 miles to the gallon (mpg). And lastly, a wide range of sports publications estimate that a running human burns about 100 kCal per mile.

Next, we need to harmonize these units for a useful comparison. I will spare you the math and give you the conversion factors. I assumed here the EPA's equivalent figure of 33,700 Wh in each gallon of gasoline. The factors that matter are:

1 kCal/mi = 1.162 Wh/mi = 0.00003449 Gal/mi

Summarizing into one table, we get:

I took the liberty of adding electric bikes and the Tesla Model S to the mix as well as adding an approximate gross weight for each mode, noting that the weight of the bikes do not include the weight of the rider. So what are the results telling us?

First, something we already knew or suspected: An electric car is about 4 to 5x more energy efficient than a sedan with a gasoline-engine. This is primarily due to the fact that an electric motor is more than 90% efficient, whereas a gasoline engine is near the 20% mark...in other words, 80% of the energy in a gasoline engine is lost to heat, and only 20% is used for movement.  Go EVs!

My bicycle is nearly 4x more efficient that my Ford Focus Electric. That is a little odd because the human body is not a very efficient machine. So why is the bicycle powertrain more efficient that this ultra-efficient electric motor? The answer is weight! A bicycle with a rider weighs 1/20th the weight of an electric car.  The Tesla Model S is considerably heavier than my EV and consequently consumes more energy. The next time you wonder why the Toyota Prius has better fuel economy than a regular sedan, think weight. Geez, we kind of knew that, didn't we?

But now, we start making observations that are less intuitive. An e-bike is more efficient than a bike, which in itself is more efficient than a human running, yet all three are sufficiently close in weight. The human body is mechanically not very efficient, especially when compared to the power train of a bicycle. The rolling motion of a bicycle lends itself to lesser friction than walking and running, and is thus more efficient. An e-bike replaces the rider with an electric motor that is more efficient than his or her leg muscles -- though not as healthy!

So what does it all mean? First, electric-powered transportation is the way of the future -- as long as we are not getting the electricity from dirty coal-fired power stations. Second, shed the weight, and that is the weight of your vehicle, and your own weight if you like to ride. Third, a banana provides a human being with about 105 kCal, or equivalently, 120 Wh of energy. That can power a human rider on a bike for 2.5 miles. No power-generator can turn a banana into sufficient electricity for any useful purpose. In other words, while electricity looks green and clean, by the time we consider its cost of generation both in dollar terms and impact on the environment, it probably cannot compete with a healthy banana. Besides, eating a banana beats all forms of fast-charging....Be safe in all your travels!

© Qnovo, Inc. 2015 / @QNOVOcorp @nadimmaluf #QNOVOCorp    http://www.qnovo.com

64. ON MOORE'S LAW AND SNAIL'S LAW                                                      

It's all over the media: Moore's Law just turned 50! What is Moore's Law? It's more an observation than a law, but it has stuck around, now 50 years, that we think it is a law, like gravity.

On 19 April 1965, Gordon Moore, at the time the head of R&D at Fairchild Semiconductor, and later the CEO of Intel, made an observation turned prophecy. He predicted at the time* that the number of components and transistors on an integrated circuit (IC or chips) would double every approximately 18 months while holding the cost of the chip constant. In layman's terms, it means that the industry will be able to double the complexity, and hence the computational power, of these chips every roughly 1.5 years without increasing the cost of the function. And for 50 years, this prediction held remarkably well and has been hailed by the tech and semiconductor industry. 

Its implications are just spectacular. Next time you hold a smartphone in your hand, pause for a moment and think about the fact that it is thousands of times more capable than the Apollo Guidance Computer that landed Neil Armstrong and Buzz Aldrin on the moon. Moore's Law is in some ways the new Bible of the tech industry with an implicit expectation that all new technologies ought to follow this trend. But is that true? and specifically, is it and will it be true of energy storage and battery systems?

Left: Processor power measured in MIPS shown on a logarithmic scale         Right: Battery energy density in Wh/l

The answer in a nutshell is a big fat NO! Whereas history has shown that semiconductors follow Moore's Law, that same history shows that the trend in batteries is closer to the progress of gastropods, hence, Snail's Law. The two figures above illustrate the difference. From 1995 to 2015, the computational power of processors made by Intel increased by a factor 300X, effectively doubling every 2 years. In contrast, over that same period of 20 years, the energy density of lithium-ion batteries increased by 4X, or less than 7% annually.  No one disputes this fact because most consumers complain about their batteries, and few, if any, complain about the processor or the electronics in their devices. But why is that? They both involve materials and manufacturing, yet the differences are stark.

It boils down to a balance between the laws of physics and economics. The laws of physics dictate the amount of technical improvement that is possible given a scientific and/or engineering problem. In the case of semiconductors, these were the laws of physics that dictated the shrinking of the dimensions of transistors in a silicon chip. Back in 1965, these transistors did not operate anywhere near the fundamental limits of materials or equipment. So physics were not the limiting factor in this balance, but economics were. In other words, the R&D and manufacturing costs associated with shrinking transistors had to increase at a lesser pace than the technical performance of these transistors. Under such a circumstance, these added costs were amortized over a rapidly increasing technical performance, and hence the benefit of Moore's Law: more performance for the same cost point. Said differently, shrink the dimensions more, get more benefits, and this equation becomes seemingly a virtuous circle....that is until it starts to hit the limits of physics, at which point the balance tips -- something that the industry may be soon facing.

For batteries, that balance between technical limits and economics was really never in place. First, the cost of R&D and manufacturing was not offset by increasing performance, in particular, energy density. In other words, every increase in energy density manifested itself initially as an increase in unit cost. So there really was never an equivalent to Moore's Law's cost-constancy. As a matter of fact, as we examine closely the economics of lithium-ion batteries over the past 20 years, we find that the cost of these batteries declines as a function of cumulative production volumes, not annual production volumes. This is a much slower cost curve and is partly responsible for why raising R&D investments for battery research does not make a lot of sense to battery manufacturers. There is more supporting evidence in the fact that battery vendors live on single-digit gross margins, whereas many semiconductor companies have gross margins close to 50% -- i.e., much better profitability.

Second, lithium-ion batteries are already hitting some serious material and physical limits. The presently used material systems in lithium-ion batteries seem to saturate right around 650-700 Wh/l. Going above these figures means higher R&D and manufacturing investments for new materials, and these costs are difficult to amortize.

The result is that energy density begins to level off or improve at an increasingly slower rate. Yes, a breakthrough from a university research program or an innovative company may change that, but history has shown that such breakthroughs don't come from wishful thinking, but rather from years and billions of dollars in research, both of which are becoming scarcities in batteries. 

But that may not be such a bad thing. When technologies begin to level off, cost pressures rise immensely as better manufacturing methods are introduced and as more competitors, especially in low-cost geographies, join the fray. So that means costs will drop rapidly -- this perhaps may be the implicit corollary and inverse of Moore's Law. In mathematical form, we can anecdotally write this as Snail's Law = 1/[Moore's Law].

In summary, I believe that the battery industry is entering a new era with accelerating cost pressures, accompanied with a shift to improving the performance of the entire battery system that includes the individual cells, the control electronics, algorithms and software. And that will bode well to companies that are skilled in this system integration exercise , regardless of the application and end-market.

*You can read here Dr. Moore's original article from 1965 reprinted in the Proceedings of the IEEE

© Qnovo, Inc. 2015 / @QNOVOcorp @nadimmaluf #QNOVOCorp    http://www.qnovo.com

63. WHY I WILL NOT BUY THE TESLA POWERWALL SOON      

Tesla Motors announced a few days back its new battery pack for the residential market. Called the PowerWall, it will be offered through Tesla's sister company, SolarCity, to residential customers. Tesla says that this home battery will allow consumers to charge it using solar panels to power their homes at night. Alternatively, consumers can charge it at night when electricity prices are low, and use this stored energy during the peak-rate hours, often in the afternoon hours. In the parlance of utilities, this is called "peak shifting," i.e., the consumer gets to shift the load. In financial terms, this is called arbitrage, i.e., buy energy at the low price, then sell it (or use it) when the price is high.

Tesla's PowerWall is rated at 10 kWh with a smaller product version rated at 7 kWh. SolarCity advertises that the fully installed cost of the PowerWall is $7,140 + tax, which would be a total of $7,730.

So let's decipher these numbers and see whether they make sense to a residential home. To make the analysis simple, I will offer my own electricity usage as a model to determine whether our home is a candidate for the PowerWall. Fortunately, PG&E, our utility, offers through its website a detailed log of our electrical usage, hour by hour. So I downloaded our home usage data and analyzed our consumption of electrical energy as well as our rate -- in other words, the amount we pay for each kWh of electricity that we consume. For the analysis, I used the data for four representative months during 2014: January, April, July and October, or the first month in each quarter of the year. 

First, let's see how much electricity we utilized. In January, we used on average of 26 kWh per day; in April the daily average was 22 kWh, rising to 28 kWh in July then dropping to 19 kWh per day in October. Again, these are daily averages over the entire month in consideration. So on average, it nets out to about 24 kWh per day over the four seasons. According to PG&E's analysis of our data, our electricity consumption ranks in the middle of the range of "similar homes." I am not sure what it really means, but I will take it as saying that our daily averages are good representations of many homes in our area.

Given our average daily utilization, let's amortize the cost of the PowerWall over the expected 10-year lifespan of the battery. Simple math gives us a cost of $2.15 per day just for the battery capital cost, or about $0.09 /kWh, again, just for the cost of the battery itself, i.e., it does not include the cost of the electricity to be stored.

Now let's assume that I would want to use this battery to offset my peak afternoon pricing by purchasing the electricity at night on the cheap, storing it in this battery, then using it during the peak hours. This arbitrage would necessitate that the rate differential from PG&E, i.e. the difference in electricity price between the peak rate and the low rate, ought to be more than the $0.09 / kWh just to break even. In reality, it ought to be substantially bigger for me to realize some meaningful savings. The bigger the differential, the more the savings. If the differential is small, then the economics of the battery will simply not make sense.

The next chart shows the actual rate ($/kWh) I paid to PG&E during the four months in consideration. Our plan is a time-of-use which means our rates fluctuate during the day and seasonally. For the months of January, April and October, the lowest rate was about $0.12 /kWh. This is low for the day, but not as low as one may read in the papers about the rates in Texas -- these could hit a low of $0.05 /kWh. My peak rate in January and April was a little over $0.20 /kWh, so the differential in January and April was marginal and not very economically compelling. The peak rate in October climbed to $0.35 /kWh, so that made the battery more interesting for the month of October. 

But here's the real shocker. My low rate in July jumped up to $0.20 /kWh at midnight, nearly double what it was in January...ouch, PG&E! It's a shocker because the rates that the utility will charge me, both the low and high rates, are subject to change in the future. I have no control over these rates, yet by buying a PowerWall battery, I have now committed myself to a period of 10 years to recoup my money using a mathematical formula that is almost guaranteed to change in time. So the risk is all mine but my upside is minuscule and questionable over these 10 years. This is not an economical incentive. This is a recipe to give Tesla and SolarCity a great upside opportunity while shifting the economical burden onto residential consumers. The math simply does not work out. Tesla needs to drop their battery prices further and the utilities need to support this effort (i.e., not torpedo my potential savings by raising the lowest rates in the future) before I can feel that there is a stable financial incentive for me. Until then, I will not be buying a PowerWall any time soon. As Christopher Helman at Forbes accurately pointed out, this Tesla home battery is another toy for rich green people.

© Qnovo, Inc. 2015 / @QNOVOcorp @nadimmaluf #QNOVOCorp    http://www.qnovo.com

62. YOUR WATCH BATTERY IS REALLY CHALLENGED                             

Apple just released its Apple Watch joining a growing list of manufacturers of new smart watches, including Samsung, LG, Motorola and others. These watches include, in addition to timekeeping, features such as messaging, basic email, navigation, in some cases voice calls, health & sports monitoring, as well as a slew of growing apps that seem dedicated for this tiny screen on the wrist. For the most part, they seem so far to be an extension of your mobile device, with the Apple Watch extending the reach of the iOS ecosystem, and the other watches performing the same for the Android ecosystem. Let's examine in today's blog the batteries used in these smart watches as well as batteries in "older and dumb" watches.

One of my favorite and practical watches is the Casio Pathfinder family. It was first introduced ca. 2001 and was the first to integrate a series of useful microsensors for the outdoorsman (or woman). Incorporating an altimeter and digital compass, it also was able to synchronize its time to NIST's universal clock broadcast radio signal out of Colorado. And it never ran out of battery juice -- it had a little lithium-ion battery made by Panasonic (CTL 1616) and was recharged by ambient sunlight. Made of a lithium cobalt titanate chemistry, this little cell had a terminal voltage of 2.3 V and a charge capacity of 18 mAh, equivalent to 0.041 Wh -- plenty to power the sensors and gray-scale LCD display.

Now, let's look at the new generation of smart watches in a family portrait of their respective batteries, courtesy of various teardowns from ifixit.

These batteries have a charge capacity that is about 15X larger than the one used in the Casio watch. This is clearly not surprising since these new smartwatches consume significantly more power to operate the AMOLED display and all the radios (e.g., WiFi, NFC, Bluetooth, and in some cases, LTE).  Consequently, the batteries are physically larger and thicker, and use half or more of the smart watch volume. The CTL 1616 is a mere 1.6 mm thick whereas the cells in smart watches are twice as thick or more. Among these smart watches, the LG G Watch has the highest capacity at 400 mAh and the Apple Watch the least at 205 mAh. 

But this 15X-increase in charge capacity does not yield a longer use time relative to my decade-old Casio. I never have to worry about charging my Pathfinder but these new smartwatches seem to have a run time between 3 hours (for the Apple Watch) and 4 hours (for the Android flavors) when operated constantly, with the display and radios on the entire time. Simple math gives us a quick estimate of the power usage: approximately 250 mW for the Apple Watch going up to about  350 mW for the Android watches. Naturally, aggressive power management, fancy parlance for frequently shutting down the display and the radios and CPU, preserves the battery and extends its life to an estimated full day of use. Additionally, there is probably room to bring these power consumption figures down with time as watch designs get optimized -- time will tell.

Apple does report a charge time of 2.5 hours corresponding to a rate of approximately 0.6 C, or about 120 mA of charge current into the battery.  Measured charge times for the Samsung and LG watches appear to be in line, with the Moto 360 being a smidgen faster at about 2 hours (equivalent to 0.7 C or a charge current of 200 mA). This means that the charging power into the watch, whether it is wired or wireless, varies between 0.5 W and 1 W, considerably less than the charging power into a smartphone (which may reach up to 18 W).

So let's see if we can synthesize a coherent picture of the challenges that batteries in these smart watches face if this product category will become mainstream. First, it's imperative that the battery capacity is increased significantly past 300 mAh, the level that seems to be the norm for now. In other words, unless consumers want thick and large watches, the energy density of the cells will have to rise above the already-large figures in present batteries. This is not an easy task. Second, these batteries had better be thin. But thin and high energy density don't go well together. Third, I really don't like a 2-hour charge time. Consumers will want to see these watches off their wrists for no more than 15 - 30 minutes. So expect to see fast charging soon. Yes, that's doable. And lastly, time will tell how often consumers will replace their watches, but I bet that at $350 ea., they will need to last way more than 2 years...so has anyone yet screamed foul on cycle life.

© Qnovo, Inc. 2015 / @QNOVOcorp @nadimmaluf #QNOVOCorp    http://www.qnovo.com

60. WHAT IS CELL BALANCING ?                                                                    

We have covered in prior blogs the operation of batteries in smartphones. The vast majority of such devices use single-cell batteries. In other words, there is one physical cell that is the battery. As such, it has a given charge capacity measured in mAh or Coulombs, and it has a voltage range that is between 3.0 and 4.35V. If we stack multiple cells in an electrical configuration, then in principle, one can obtain a multi-cell battery configuration, called a pack, that can deliver more charge capacity. 

The electrical configuration of such cells defines the nomenclature - see figure below. If the cells are electrical tied in series, then the pack is called s-configuration. If they are tied in parallel, then they are in a p-configuration. The former serves to raise the maximum voltage of the pack in multiples of 4.35V, whereas the latter serves to increase the maximum current through the pack without increasing the voltage. 

Now let's examine what happens if the cells in a multi-cell pack are not identical. For example, they could be slightly different from the onset, or perhaps aged at different rates. In a parallel configuration, the voltage is always equal for both cells. Any difference in charge capacity between the cells will manifest itself as a difference in current in the two branches. In particular, this parallel configuration always guarantees that the cells do not exceed their maximum safe voltage, often 4.35V.

But a series configuration creates a different and more challenging situation. The current is shared and equal to both cells, and hence, each cell will manifest a different voltage. Let's first examine the charging of two cells in series. If the two cells are truly identical, then they will reach their maximum capacity and their maximum voltage at the same moment. But if there is a difference in capacity between them, then the cell with a smaller capacity will reach 4.35V before the other cell does. At this point time, one cell is 100% full while the other one is not. If the charging is not disconnected immediately, one cell will certainly get overcharged and cause a hazard.

To remedy this situation, electrical circuits called cell balancing are used. In principle they are simple They add a little switch and a small resistor across each cell in series. This added circuitry provides the ability to "bleed off" additional charge from the "strong" cell, so that its voltage stays about equal to that of the weak sister. This type is called "passive balancing." Naturally, this is not a very energy-efficient nor cost-efficient method, but at least it guarantees that the weak cell will not be overcharged. As we covered in prior blogs, lithium-ion cells, unlike lead-acid batteries, risk catching fire or exploding when they are overcharged above their maximum voltage, typically 4.35V for one individual cell.

Let's now examine discharging two cells in series. The figure below shows the voltage vs. charge curve for two similar but slightly different cells. They are both nominally 7,000 Coulombs (or about 1,900 mAh) but in reality, one cell is 7,200 Coulombs and the other one is 6,800 Coulombs. This is about 5% difference in capacity, and can readily happen in a pack without the proper precaution.

Let's now assume that both cells are charged to an identical voltage. For the blue cell, this will correspond to a stored electrical charge of 3,600 Coulombs, or about 100 Coulombs more than its sister cell. Let's now start discharging the cells in series; in other words, the exact same discharge current flows through both of them for exactly the same duration of time. This means that both cells will lose the same amount of charge; for the purpose of this discussion, we assume it is 3,000 Coulombs. We notice from the figure above that the blue cell will have a terminal voltage across its cells that is higher than the red cell (the more aged cell). Any further discharge will cause the red cell to drop precipitously and cause it further degradation, effectively over discharging the cell. This is not an unsafe event but it is a phenomenon where the weak cell (the red cell) will actually degrade at a faster rate in a series configuration. This is why it is always said that a "pack is only as good as its weakest cell." In other words, without the use of clever algorithms and balancing, the cycle life of the entire pack will be equal to the cycle life of its weakest cell.

Battery-pack manufacturers try to minimize this problem by matching the cells in a pack as much as possible. It is very common for pack manufacturers (including makers of electric vehicles) to measure the capacity of each and every cell in a pack, and matching the cells to within less than 1% in charge capacity. But as one will immediately observe, this gets very expensive especially for large packs as the yield of useable cells can be quite low.

In some extreme cases, some packs can utilize "active balancing." This includes more sophisticated electronic circuits that will actually shuffle charge from the strong cell to the weak cell. The effect is to increase the cycle life of the pack by shoring up this weak cell and ensuring that it does not get overcharged nor over-discharged.

It is important to close here by saying that the vast majority of mobile devices use single cell configuration, and hence do not implement cell balancing. Most laptop computers and some tablets use 2S configurations (two cells in series). They often implement rudimentary passive balancing. For example, the Apple MacBook series of products often use the bq20zxx family of fuel gauges with integrated cell balancing from Texas Instruments -- such consumer-grade fuel gauges can handle cell balancing for small packs up to 4 cells in series.

© Qnovo, Inc. 2015 / @QNOVOcorp @nadimmaluf #QNOVOCorp    http://www.qnovo.com

59. THE ANATOMY OF AN IPHONE 6                                                                     

NASA landed in July 1969 the Apollo 11 on the surface of the moon. Along with the famed astronauts was the Apollo Guidance Computer (AGC), a 1960s-era computer to navigate the spaceship to the moon and back.  A reliable machine for its time, it stands today only as a relic. A modern smartphone, for example the  Apple iPhone 6, is about 25,000 (yes, thousand) times more powerful, yet a a tiny fraction of the cost and size of the AGC. This early computer had to be powered by three gigantic silver-zinc primary (non-rechargeable) batteries with a total capacity of 3.4 kWh (enough to power a modern house), whereas the iPhone 6 takes its power from a modest 7 Wh rechargeable battery. This picture puts into perspective the marvel of modern electronics: in essence cheaply packing immense computational power into a small volume, and drastically changing our daily lives. As we have peeked in the past inside a Tesla electric vehicle, let's take a closer look at the inner working parts of the iPhone 6, an icon for modern smartphones.

This blog is not about making another teardown of the iPhone 6 -- these are abundant on the internet. Instead, I will build on them to give you additional insight into how these various components tie together, and ultimately, how they relate to power consumption and battery use.  Opening an iPhone 6 reveals, in addition to the battery and display, a printed circuit board, called the main logic board, that includes a large number of integrated circuits (IC) and other small components. This is the "brain" (so to speak) of the mobile device, and is responsible for the bulk of its power usage. Let's take a closer with photographs of the front and back sides, then begin to decipher the various sections and their functions.

Photographs of an iPhone 6 teardown showing the main logic board, both front and back. Courtesy: iFixit

First, one observes that the battery takes up a substantial space of the mobile device. This is exactly why energy density is so important. Space, hence volume, is limited yet the energy demand on a mobile device is increasing. This dictates that energy per unit volume, i.e., energy density should increase, at least as fast as the energy demand of the device will in the foreseeable future. That has been and will continue to be a challenge for the industry.

Next, one observes some obvious large sections. One the front side, the main processor, the Apple A8, is very noticeable and takes up a significant part of the logic board. What you see is actually a little module that incorporates the A8 processor chip along with its 1GB of RAM (memory). At its peak operation, this processor can consumer several watts of power as I discussed in an earlier blog. The nanoSIM card holder is also quite substantial.

To the far left of the A8 processor is the wireless section highlighted in the yellow rectangle. This is where the wireless radio frequency (RF) signal is received from the antenna, then amplified before being read by the electronics, and in the opposite direction, amplified before being transmitted by the antenna. These power amplifiers (because they increase the power of the incoming signal) are provided by companies such as Avago, Skyworks and RF Micro Devices; they  are also responsible for significant power consumption (i.e., heat) with the mobile device (up to several watts), especially if the cell tower is distant. One also notices a small chip called envelope tracking. This particular IC is made by Qualcomm (QFE1000) -- albeit there are several other suppliers too -- and is responsible to adjust the voltage supply to these power amplifiers only to the amount needed to efficiently operate them; the result is some nominal power savings and less heat generation. Envelope tracking did not exist a few years ago; this added chip (and ergo cost) is strictly to help conserve the limited battery resource.

At the core of the wireless functionality is the LTE multimode baseband chipset made by Qualcomm (MDM9625M) shown in the photograph above by an orange rectangle labeled "LTE radio." It is responsible for managing, encoding and decoding the wireless signal, both data and voice, on the 3G and LTE bands, and do it at an extremely fast speed -- 150 Mbps in this particular case. This type of products is big business for companies like Qualcomm, Intel and MediaTek. 

Above the Qualcomm baseband chip one finds a gyroscope and accelerometer combination chip made by Invensense (MP67B). This MEMS device incorporates a total of 6 sensors: 3 accelerometers to measure acceleration in the 3 basic directions, and 3 gyroscopes to measure rotation. The  teardown also identifies a 2-dimensional low-g (i.e., sensitive) acceleration sensor from Bosch (Sensotec BMA280). I suspect that is the inclinometer -- it can tell which orientation the screen has been tilted.

The back side of the logic board is home to a number of functions, some visible to end users, and others less so but equally critical. Let's start with the visible functions.  First, there is the M8 coprocessor. This is a low-power ARM processor that can handle basic functions like motion without the need to wake up its more power-hungry big brother (the A8). There is also the flash memory for data storage -- this is where you store your music and photos. Then, there is the WiFi module, built by Murata (339S028). It provides fast WiFi connectivity 802.11a/b/g/n/ac. That same module appears to also provide Bluetooth connectivity. 

Apple Pay functionality is centered around the NFC module which includes both NFC wireless connectivity (that's the wireless link between your iPhone and the payment station) as well as the secure element that Apple says provides the encryption behind this secure payment method.

Now we transition to lesser visible but quite critical functions. The touchscreen controller made by Broadcom (BCM5976) handles the display functions including reading the finger swipes on the screen. There are also two power management integrated circuits (called PMICs), a primary one made by Dialog Semiconductor and another one made by Qualcomm (PM8019). The primary PMIC provides a number of critical functions such as providing voltage rails to the logic board as well as battery charging. This is also where the primary battery management functions tend to reside though details tend to vary across PMIC suppliers. It is likely that the PM8019 provides and maintains the voltage rails specifically to the Qualcomm baseband chipset. It is not clear whether the fuel gauge functionality is integrated within the Dialog PMIC or whether it is integrated into another fuel gauge chip within the battery itself (and hence not visible by this particular teardown). Public teardown reports of prior iPhones and MacBooks have shown that Apple tends to place the fuel gauge, often made by Texas Instruments, right on the connector cable between the battery and the logic board. It's not clear whether the iPhone 6 follows this same architecture.

Naturally, what a teardown fails to reveal is the richness and depth of embedded software that resides with the multitude of chips on the logic board. Many of these chips above have some type of intelligence on board; of course, the A8 processor is by far the most capable, but even the NFC chip has a small processor (called a controller) on board, and it too needs a certain amount of intelligent software to have it run efficiently. 

While the iPhones have been some of the most observed and torn down smartphones, the concept of high density integration applies to all modern smartphones. The space is tight and cost is paramount, and that will continue to drive innovation in this market. In parallel, and equally important, there is a race to implement ever more intelligent software to extract the most performance and operation from the immense amount of computational power that now resides inside a mobile device. Richard Feynman's challenge in 1959 on "There is plenty of room at the bottom" can now take on a whole new meaning and aspiration.

© Qnovo, Inc. 2015 / @QNOVOcorp @nadimmaluf #QNOVOCorp    http://www.qnovo.com

58. SAMSUNG, BE HONEST IN YOUR MARKETING CLAIMS         

Samsung announced in September 2014 its GALAXY Note 4, a giant but elegant 6-in screen smartphone with a specified battery capacity of 3,220 mAh. It also made a bold claim that it charges the smartphone to 50% in 30 minutes.  The marketing snippet below comes straight from their website. So, how honest is Samsung in their marketing claim of fast charging? Let's find out.

We set out to test the Note 4 in our lab. We conducted charging cycles, measured the charging current into the battery as well as the battery capacity and the corresponding state of charge (the percentage the user reads in the top part of phone screen). The measurements were done with the accompanied Samsung fast charging adapter, with all wireless functions turned off, GPS and location services turned off, and the display turned off. These ensure that the current provided by the AC adaptor is entirely used for charging the battery and no other function. The smartphone was completely discharged before initiating the charging. The battery was deemed fully charged (100%) when the charging current dropped below C/20, or 1/20th of the rated capacity; this is equivalent to the charging current dropping to 3,220/20 = 160 mA. This metric is a commonly used standard of full charge in the lithium-ion industry. What were the measured results?

First, let's look at measured battery capacity. We measured a full charge capacity of 3,185 mAh, or 99% of the specified capacity. This is as accurate as one can measure it. Kudos to Samsung for being honest about the capacity...but Samsung's marketing and engineering departments decided to stretch the truth in their claims on charge time and state of charge. Let's examine these next.

Measured charging current (red) and corresponding state of charge (purple) for the tested Note 4.

The next chart shows the state of charge (as a percentage of full capacity) on the left hand side (corresponding to the curve in purple), and the charging current (in mA) on the right hand side (corresponding to the curve in red). The state of charge is what the Samsung fuel gauge software reports at the top of your screen. 

The first observation we make is that the fuel gauge reports 50% in 37 minutes, not 30 minutes as claimed by Samsung. Ok, Samsung, is 37 minutes equal to "about 30 minutes"? Perhaps if these extra 7 minutes don't mean much to a patient consumer, but I can't see how an end-user in a rush to catch their next connecting flight won't notice these precious seven minutes.

The second observation is where the phone reports 100% full charge, or the total charge time. Focus your eye on the purple curve right about 90 minutes of charging time. Right there, the fuel gauge almost instantly jumps from 94% to 100%. In other words, the software in the Note 4 decides that 94% is full enough to "round it up" to 100%.  The actual full charge time, i.e., when the battery does reach its specified 3,220 mAh is 120 minutes, but the smartphone tells you (incorrectly) that it is fully charged a whole 30-minutes earlier! That's nearly 200 mAh of capacity, or about 1 hour of usage, that you have been cheated. Ouch! Shame on you Samsung!

The third observation is that Samsung is using straight CCCV charging. Judging from these charts, their charge rate is approximately 0.75C, only a hair faster than the iPhone 6 or 6Plus which clock in at 0.7C.  So, are we now claiming fast charging at these low levels? Why can't you promise the end users 1C or above, and then proudly advertise fast charging.

Please, please, be honest about your marketing claims, Samsung. Consumers are no dummies...they will eventually realize that you are stretching the truth in your marketing claims.

© Qnovo, Inc. 2015 / @QNOVOcorp @nadimmaluf #QNOVOCorp    http://www.qnovo.com

57. UNDERSTANDING POWER USAGE IN A SMARTPHONE                           

You are shopping for a new smartphone and you are trying to understand how long the battery will last. But you can't seem to get a straight answer. Apple says the iPhone 6 will last up to 14 hours of talk time on 3G but you are really not going to have your iPhone glued to your ear for 14 hours. Motorola is more subtle about its claims: up to 24 hours of mixed use. Other manufacturers follow the same strategy of being vague about their claims with the operative word being "up to."  

The reason nobody wants to commit to battery life is you, the user and consumer. We each use our mobile device differently. Some of us use the device as a phone more frequently, others use apps more intensively. Some of us turn off plenty of background services such as data refresh, whereas others want their GPS operating with as many apps that request it. This creates an infinite number of combinations of use, and hence makes the "average user" profile somewhat of an oxymoron. This blog will shed some insight onto what components and features in your mobile device are power hungry and what you can do to limit the times that these power-hungry features are allowed to access your limited battery capacity.

The most power intensive components in a smartphone are the display, the processor (or CPU), the various radio functions (and there are several radios in your smartphones), the location services, in particular the GPS system, and the memory, in particular, writing into memory. Naturally, they are not equal in their power consumption, so we will attempt to put some power figures for each of them as well as rank them in terms of their power needs.

1. Displays: The display and its associated electronics (backlight, touch screen controller, graphics processor) are by far the most power hungry component in your mobile device. Modern smartphones have some pretty impressive displays but the more pixels they pack, the more power they consume. The Galaxy S6 has a spectacular 2560 x 1440-pixel Quad HD display but I can imagine it will be a serious power hog. Naturally, Samsung will not share these power figures with the public but one can estimate from various publications and lab tests these power levels to be about 1,000 mW for a standard 5-in HD display, and rising to 1,500 mW for the quad HD screens. A battery with a capacity of 2,600 mAh or equivalently 10,000 mWh, this translates to about 6 - 8 hours of active screen time. A couple of years back, these power levels were nearly half what they are now because the screens were smaller and were at most 720p. Tidbit #1: If you must have a large screen, reduce the backlight screen intensity. Backlights can consume several hundred milliwatts.

2. Processor: A an octa-core running at 2.4 GHz all the time will most likely cause a thermal shutdown of the smartphone quite rapidly. A processor running at full steam will consume 3,000 mW at its peak -- and generate a lot of heat. Fortunately, these peak events are short-lived and may be infrequent depending on your usage. But still, applications that are processor intensive will invoke that processor horsepower more often than you desire and deplete your battery. Rogue applications are clearly detrimental to battery life. On average,  iOS is more power-conscious and tries to reduce the demand on the processor. The new Android 5.1 Lollipop has gotten much smarter in this segment than its predecessors, but can still benefit from more improvement.  Tidbit #2: While the OS should in principle terminate applications not in use, keep an eye on rogue apps that continue to run in the background or when you don't need them. Shut them down or better yet, remove them from your device.

3. Networking and radios: Your smartphone contains several radio systems. A modern device will have a LTE radio and a separate 3G radio, and possibly an older 2G radio. It will have a separate WiFi radio and a bluetooth radio, albeit these two are usually low-power, relatively speaking. These radios have power amplifiers for their transmit-receive functions. These power amplifier consume a lot of power -- to amplify the signal -- when the network signal (the number of bars on the top of your screen) is really low. In other words, if your signal level is low, the smartphone will compensate for that by boosting its own transmission power, hence more power consumption. How much power: what is an average power of 1,000 - 1,500 mW could double or more. Tidbit #3: Turn off unnecessary radios (WiFi, bluetooth or LTE radio if there is no LTE signal). Turn off background data refresh and do not let apps have unfettered access to the network radio (especially 3G and LTE) in the background. 

4. Location services: The location services utilize an integrated chip that includes a GPS transceiver complemented by another integrated chip with accelerometers and gyroscopes. A GPS chip will consume approximately 25 mW and the accelerometer/gyroscope will consume another 25 mW -- that's 50 mW in total. It surely is far less than the radio and screen, but in a world of limited power budgets, every mW counts. Tidbit #4: More and more apps are requesting to access locations which turns on these services and consumes power. If you don't need them, turn these background location services off, and limit them to only the apps that are essential, such as navigation. Also, terminate the apps that use location services if you are not using them. Google Maps and other map apps are apps that like to check your location frequently. Terminate it if you are not using it.

5. Data storage: For most users, we don't write into memory very frequently. Memory includes the flash memory in your device (those 32 or 64 GB that hold your files and music and photos), as well as the SD Card that boots your storage by a large amount. But if you are a user who loves to use the camera feature continuously, more importantly the video, then you may be in for a surprise. Each MB file consumes a peak of 400 mW of power to be written into memory. Uncompressed standard HD (1080p) video file is 3 MB per second. Assuming an optimistic 10:1 file reduction after compression, that translates to 120 mW for each second of recording. The newer 4K video format has a whopping uncompressed bitrate of 40 MB/sec. That will be a serious power hog! Tidbit #5: If you want to record video on your smartphone, reduce the resolution to the minimum you are willing to live with. You will be surprised to see how great the 720p quality looks on the screen.

© Qnovo, Inc. 2015 / @QNOVOcorp @nadimmaluf #QNOVOCorp    http://www.qnovo.com