Tuesday, September 30, 2014

15. WHAT'S THIS STEP CHARGING?                                 

I covered in the prior post about the ill consequences of charging a lithium-ion battery using constant current, constant voltage (or simply CCCV). The damage incurred within the battery during charging with CCCV is attributed to a series of undesirable side reactions that effectively reduce the effectiveness of the primary energy storage reaction. In other words, during charging, one desires that all the energy goes into the ideal reaction that stores energy inside the battery. In reality, CCCV charging promotes a number of bad reactions that effectively damage the internal structure of the battery, and reduces the battery's ability to store electrical energy.

I will not go into the details of these side reactions; they are fairly involved and can be quite complex for the average person. But they are reasonably understood by our scientists. For example, one of them is the formation of lithium metal deposits when lithium ions combine together. Others relate to the physical damage to the electrodes and the decomposition of the electrolyte solution.

A few of these undesirable side reactions, but certainly not all of them, have been shown to exhibit a dependence on voltage. Specifically, some of the damage accelerates when the voltage of the battery approaches 4.35 Volts....or in other words, when the battery is approaching 100% full charge. This is why a common tip is to charge the battery up to about 80% instead of the full 100%. 

So step charging, probably introduced several decades ago, was an early attempt to charge the battery very gently at the higher range of voltages, or when the battery is approaching full. It is simple: it means reducing, or stepping down the current, when the battery voltage reaches say 4.1 Volts, or say around 60% or 70% of its maximum charge. However, extensive tests and results over the past many years have shown that the damage reduction was at best minimal. There were indeed a few cases where step charging seemed to have helped, but these were few and far in between, and worse yet, there was not much consistency. In other words, step charging did not deliver a solution.

I will leave the discussion of better, more sophisticated, charging methodologies to another post, but let me address here why step charging fundamentally is flawed or at best, incomplete.

First, step charging is only attempting at alleviating the amount of charging when the battery is nearing its highest voltages. But the damage to the battery is not only due to high voltage. It is due to more complex reactions of which voltage is but only one parameter. Failing to recognize the relationships between all the damage elements makes step charging quite ineffective. This is particularly acute in more modern lithium-ion batteries with high energy densities (or higher capacities). 

Second, step charging, much like CCCV, is an open loop solution. In other words, it has no knowledge of the battery's inner reactions, inner health, inner status, and consequently  has no means to measure or assess the rate at which these undesirable damaging reactions at taking place. So let's say for the sake of example, we have two batteries from the same type and vendor, but with  manufacturing variations between them (which is very common). Let's further say that one battery is better, and that its damage seems to occur at an onset voltage of 4.1 Volts. Let's also say that the difference in manufacturing causes the damage in the second battery to occur at a lower voltage of say 4.0 Volts. So if step charging reduces the charging current at 4.1 Volts, then one battery will see an improvement but the other will not. And if one were to say let's drop the charging current at 4.0 Volts to be safe and cover both batteries, then there is a serious penalty to charging times -- charge times will balloon significantly.

So in a nutshell, if someone is promoting to you step charging as a solution, my advice is simple: RUN!

© Qnovo, Inc. 2014 / @QNOVOcorp @nadimmaluf #QNOVOCorp    http://www.qnovo.com

Monday, September 29, 2014

14. WHY IS CHARGING WITH CCCV BAD?                                  

CCC...what? Yes, it is a mouthful and it stands for "constant current constant voltage." It is presently the charging approach used for lithium ion batteries. As I indicated earlier, it was invented in the 19th century for charging lead-acid batteries, and somehow it became the default charging methodology for present-day lithium-ion batteries. This is what your smartphone, tablet and your electric vehicle do to charge your lithium-ion battery.

As the name implies, the electronics in the battery management system (see the earlier post on BMS) charge the battery initially with a constant amount of charging current. The higher the charging current, the faster the charging time; and consequently, the higher the power; and therefore, the bigger the AC adapter (or wall charger) to accommodate the higher power rating. That's why a tablet adapter, typically rated around 12 Watts, is bigger than a typical smartphone adapter which is rated at or near 5 Watts. And that's why an electric vehicle requires a far bigger charger, rated above 6,000 Watts.

As the battery is charged, its terminal voltage rises. A single lithium-ion battery starts near 3 Volts, and as it charges, its terminal voltage will rise above 4 Volts. When the voltage reaches a predefined limit, often 4.35 Volts, the charging electronics will switch from a constant current to a constant voltage -- this is to ensure that the voltage across the terminals of the battery never exceed 4.35 Volts. Higher terminal voltages risk the trigger of unsafe failures. Incidentally, never charge a lithium-ion battery with a charger that was not designed specifically for lithium-ion batteries.

Now a lithium-ion battery's internal chemistry is quite complex. When the battery is being charged, lots are happening inside the battery. As I explained in prior posts, lithium ions are traveling from one electrode to the other and inserting themselves within the electrode. This is all happening within the battery and is transparent to you, the end user. Alongside this charging process, as you might imagine, there are other bad and undesirable things that are happening too. For example, it is easy to imagine that all the lithium ions will travel together and happily make the journey from one electrode to another. In reality, these lithium ions will "collide" and they will bond together to form dangerous  deposits of lithium metal. These lithium ions are now out of the picture and can no longer participate in storing electrical energy. It is analogous to traffic jams on highways because cars do get into accidents; the notion that cars on a highway will travel merrily at 65 mph and stay in their own lanes is somewhat naive and left only to a utopian universe.

Now, it turns out that CCCV charging is greatly responsible in how lithium ions travel inside the battery. There is sufficient proof now that CCCV is one of the key factors that accelerate the damage inside the battery exhibited by the loss of lithium ions. Think of it as the ill-timed traffic lights or poorly marked signs on the road that can cause unnecessary accidents.

So you might ask, how come this issue was not observed in the past? Well, lithium-ion batteries of yesteryear are akin to a rural highway with very few cars on it. So even if the highway signage was defective, there were relatively few cars on the road. Batteries from past years have low energy densities, and consequently have fewer lithium ions to go around, so they were more forgiving. But modern batteries are now packing higher energy densities, in other words, they contain a lot more lithium ions than their older sisters ever did, and thus are extremely sensitive to how they are charged. This combination of high energy density batteries with CCCV charging is a recipe for excessive damage, less capacity, short cycle life, and consequently, a very poor consumer experience. 

Think about it next time you wonder why your battery seems to be losing its freshness.

© Qnovo, Inc. 2014 / @QNOVOcorp @nadimmaluf #QNOVOCorp    http://www.qnovo.com

Sunday, September 28, 2014

13. WHAT IS A BMS?                                                      

No, it is not "Batteries Made Simple," nor "Better Make Sense," though BMS do indeed try to accomplish both in a very indirect and implicit way.

BMS stands for Battery Management Systems. These are electronic systems, both hardware and software, whose primary function is to control the operation of the battery. In order for batteries, and more specifically lithium-ion batteries, to deliver the requisite safe performance, they must operate within some very well defined, and in many cases, strict limits. For example, a lithium-ion battery cannot be charged above a certain voltage specified typically by the manufacturer in the range of 4.2V and 4.35V. Maximum current values and temperature limits are other examples. Failure to observe these limits will result at the very least in performance degradation, and quite likely in a seriously unsafe outcome such as fire or even death. A Chinese flight attendant died in 2013 while using her iPhone 5 during charging; her electrocution was attributed to a counterfeit charger she purchased in China.

BMS cover several functions including charging the battery, measuring the battery's amount of stored charge, and making many decisions to ensure the battery remains within a safe operating mode. 

The fuel gauge, the device responsible for giving you the percentage of "battery full" in your mobile device, is an integral part of the BMS. Fuel gauges were practically inexistent until a startup company called Benchmarq introduced them in the early 1990s, initially for notebook PCs. Fuel gauge functionality is integrated today in the power management integrated circuits (known as PMIC) manufactured by companies such as Qualcomm and Texas Insruments, yet sadly, there has been very little if any meaningful innovation added since Benchmarq -- I will resist the temptation of openly promoting Qnovo here. For example, the accuracy of the fuel gauge in your smartphone is quite poor, and can often be as high as 5 to 10 percentage points. Next time you look at your mobile device and it reads 20% battery remaining, keep in mind that may be as little as 10% or as high as 30%. Worse yet, device manufacturers routinely fail at translating this reading into a meaningful usage number like  hours of remaining use.

Battery charging is another function of the BMS. Yet charging remains extremely primitive. Most mobile devices today charge using a method called constant-current constant-voltage (abbr. CCCV) that was invented in the 19th century to charge lead-acid batteries. Its simplicity certainly made it irresistible; but there is no free lunch. CCCV charging has now been clearly established as a primary cause of battery damage. Next time you look at your mobile device and wonder why it is not lasting you a full day as it did when it was new, you can start by pointing the finger to CCCV charging. Yet, most mobile devices still stick with this archaic charging approach.

If you are a battery user, you also might want to see additional information such as the health of your battery. Nope! You can't get it from present-day BMS in your mobile device. You may want to charge your mobile device faster. Nope! You can't do it. You may want to know whether your battery may have been defective from the onset. Nope again! Both you and the device manufacturer are in the dark. Yes, you can walk today into the store of your favorite wireless carrier (or operator) and tell them that your battery was defective, and there is virtually little they can do to prove or disprove your concern. Insist a little and you will walk away with a replacement smartphone or mobile device. And while you are at it, let them know that you want more features such as faster charging!

This is the sad state of battery management today. It's not because innovation is lacking or the technology is behind. Solutions do exist. Device manufacturers are slow to implement innovation. So let them know what you want!

© Qnovo, Inc. 2014 / @QNOVOcorp @nadimmaluf #QNOVOCorp    http://www.qnovo.com

Saturday, September 27, 2014

12. A PEEK INSIDE A LITHIUM ION BATTERY.                        

Today's post takes us on a brief journey inside a lithium-ion battery. What is its internal structure and how does it actually store electrical energy?

Let's first start with a capacitor...the kind of stuff you studied in high school physics. It has two plates separated by an insulator, for example, an air gap, or may be a thin sheet of mica. If you recall your science experiments with a capacitor, it stored electrical energy because electric charge (electrons here) was pulled from one plate, traveled across an electric circuit and moved the opposing plate. This act of separating electric charge in the basic mechanism of energy storage. Its evidence in an electric circuit is the presence of a voltage across the two plates (or terminals) of the capacitor.

So why can't we use an electric capacitor for energy storage? Simple...its energy density is way too small. But wait, you say, capacitors in our high-school physics classes were never described in terms of energy density. They were described in terms of capacitance measured in units of Farads.  No problem, we can use either methodology. Typical capacitors have capacitances ranging from a few picofarads (one pico is one trillionth) to may be millifarads (one milli is one thousandth). By comparison, a lithium-ion battery has an equivalent capacitance about one million times larger. 

So a rechargeable battery is fundamentally an electrical device for storing energy at the highest possible energy density -- or in very simplistic terms, think of it as a capacitor whose two plates are separated from each other by only nanometers (one nano is one billionth). 

The internal structure of a lithium-ion battery is remarkably yet deceivingly simple. Much as a capacitor, it has two metal plates called electrodes. In lithium-ion batteries commonly used in mobile applications, one electrode is made of an alloy of lithium, cobalt and oxygen written colloquially as LCO. The other electrode is made of graphitic carbon, the kind of material you find in the lead of a pencil.

Now here's the magic and beauty of operation. The lithium ions are present in a type of solution immersed between these two electrodes called electrolyte. When the battery is being charged, the lithium ions travel towards the carbon electrode, and physically enter the carbon matrix. The ions actually sit inside the carbon material. Think of swiss cheese and filling the empty spaces lithium ions. When the battery is discharged, the opposite happens and the lithium ions insert themselves inside the LCO electrode. Every time the ions go back and forth, energy is stored then returned. Very elegant. 

In real life, battery manufacturers build large sheets of electrodes, I mean very large, several feet wide and tens of yards in length, then assemble the sandwiched structure, then usually (though not always) roll it together in a cigar-like shape to make the device as compact as possible.

A photo showing the internal structure of a lithium-ion battery. Close examination shows the cigar-like roll containing the electrodes and the electrolyte. Courtesy of Dr. Venkat Srinivasan at the Lawrence Berkeley National Labs.
One last word on safety. Why are lithium-ion batteries prone to catching fire? It's a complex process but let me explain with a simple example. Under some extreme conditions, say if we are carelessly charging the battery over its maximum allowed limits or creating a short-circuit by punching a nail into the battery, oxygen is released from the LCO electrode. But lithium is very reactive in the presence of oxygen and immediately catches fire. And lithium fire cannot be put out with water. Water actually makes the situation worse.

The good news is that lithium-ion batteries have gotten extremely safe over the past few years as battery manufacturers have made their designs less prone to these failure, and electronic protection systems ensure that the battery never sees extreme conditions.

© Qnovo, Inc. 2014 / @QNOVOcorp @nadimmaluf #QNOVOCorp    http://www.qnovo.com

Friday, September 26, 2014

11.  DID YOU KNOW?....                                               

Did you know that the first battery was invented in 1791 by Volta using alternating zinc and copper plates?

Did you know that the first rechargeable lead-acid battery was invented in 1859?  It remains to date used in automobiles worldwide and is one of the least expensive methods to store electrical energy.

Did you know that the first rechargeable lithium-ion battery was commercially released in 1991 by Sony, nearly one and half century after the invention of the lead acid battery?

Did you know that North American universities graduate lots of electrical and software engineers, but that very few universities have programs to graduate chemists or chemical engineers specialized in batteries? As a result, talented battery experts are hard to find.

Did you know that lithium-ion batteries and lithium-ion polymers refer to the same battery mechanisms, but may differ only in their form factors? Polymer batteries are thin and flat to fit inside a device. They can be made to custom dimensions.

Did you know that lead-acid batteries last a long time if they are kept fully charged, but lithium-ion batteries are much happier if they are left about half-full?

Did you know that present-day lithium-ion batteries are recharged in the same way lead-acid batteries were charged in the 19th century? The charging is called by the mouthful and uninspiring name of "constant-current, constant-voltage."

Did you know that batteries, and in particular lithium-ion batteries, are completely unhappy if operated at temperatures colder than 10 degrees Celsius and above 40 degrees Celsius? Did you leave your smartphone on your dashboard at noon?

Did you know that when you are told to discharge your lithium-ion battery to zero and charge it back to 100%, it has nothing to do with the battery itself? When you cycle the battery from a total empty to a full charge, all you are doing is recalibrating the fuel gauge (the silicon chip responsible for measuring how much charge you have left in the battery). The cycling does nothing to the battery itself.

Did you know that lithium-ion batteries, unlike the older nickel-cadmium ones, do not suffer from memory effects and cannot be refreshed or refurbished?

Did you know that over 90% of lead-acid batteries in the USA get recycled, yet, and most unfortunately, exhausted lithium-ion batteries end up in your local garbage dump?

Did you know that lithium is fairly abundant in the Earth's crust (in the form of lithium-salt ores) and you should not worry about running out of lithium in the foreseeable decades?

Did you know that the safety concerns of lithium-ion batteries stem from the reactivity of lithium, in particular with oxygen or water? 

Did you know that solid-state batteries, i.e., batteries made of all solid components and manufactured using semiconductor-like processes, do exist and can be purchased commercially, but they suffer from very low charge capacity?

© Qnovo, Inc. 2014 / @QNOVOcorp @nadimmaluf #QNOVOCorp    http://www.qnovo.com

Thursday, September 25, 2014


So you are happy with the large battery in your new iPhone 6 Plus. Finally, Apple listened and put a large, nearly 3,000 mAh, battery in your device. Finally, Apple followed the rest of its Android-based competitors who already had scaled their batteries to sizes between 2,500 and 3,200 mAh. So what do you think these batteries will be in 2015, or even past that, say in 2020! Surely, we must expect batteries with capacity over 4,000 mAh or even 5,000 mAh. Yes, surely you are joking!

Let's get geeky for just one brief moment. Let's talk about energy density. That's the amount of energy that one can pack in a known volume, say a gallon or a liter. Battery energy density is measured in units of Watt-hours per liter (Wh/l). State-of-the-art batteries in the market today boast of an energy density between 600 and 650 Wh/l. Prototypes in the lab are somewhere between 700 and 800 Wh/l depending on whom you choose to believe. Mobile device makers would like to see 1,000 Wh/l. Great, I admire setting ambitious goals, but let's see how feasible it is.

The present material system uses a special alloy called cobalt-oxide as well as graphite (carbon) for the two electrodes of the battery. This particular material combination has already hit the wall in terms of energy density; somewhere between 600 and 650 Wh/l. So to go past this limit, manufacturers are exploring new types of materials, with silicon or silicon-carbon composites being one such candidate. Early results are promising but scaling the manufacturing remains several years away. Additionally, the cost of building these new high-energy density batteries is rising, driven by more complex manufacturing processes, more expensive materials, more R&D resources, more expensive capital equipment, and more rigorous quality-control steps. Low-cost batteries out of China are now about $0.10 per watt-hour. These new high-energy density batteries can be easily 5 if not 10x more -- well, that is if you can find them. They still don't exist in commercial scale.

So here's the conundrum for mobile device makers. They want more capacity without making the mobile device bigger. But batteries with such high-energy densities still don't exist in commercial scale. And if they did, they would be terribly more expensive in a mobile industry where cost pressures are enormous. Then, they are at a point now where their trust in the battery manufacturers is at best shaky. Battery manufacturers have long promised more capacity and better batteries but have struggled to deliver. Instead, several battery vendors chose to play juvenile gimmicks with their battery specifications to cover their shortcomings. 

So if you are a mobile device manufacturer, you either recognize you have a serious problem, or if you don't, it's time to wake up and smell the coffee!

© Qnovo, Inc. 2014 / @QNOVOcorp @nadimmaluf #QNOVOCorp    http://www.qnovo.com

Wednesday, September 24, 2014

9. WHY ARPA-E HAS GOT IT WRONG?                                  

For those of you who are not familiar with ARPA-E, it is an acronym that stands for Advanced Research Projects Agency - Energy. It is an agency of the U.S. Department of Energy, and was formed in 2007 by the America COMPETES Act with the intent to emulate the success of its counterpart, DARPA, at the Department of Defense. Its charter is to promote advances in sciences related to energy, translate discoveries and inventions into innovations, and accelerate advances that industry is not likely to undertake.

From its early days, ARPA-E identified energy storage, and in particular battery technologies, as an area of focus and investment. Since 2009, ARPA-E has invested tens of millions of dollars into this research area, of which significant funds went to support research into new battery materials. In 2009, the White House announced that they would make $2.4 Billion in grants available for the development of batteries and power drive components for electric vehicles, installation of charging stations and other programs aimed at advancing the US EV industry.

Several programs benefited from this funding over the past five years. We see far more EVs on the road, especially here in California, than we ever did in the past. It helps immensely that the State of California has offered an additional set of incentives in parallel.

However, the one area that showed little progress if any despite the flow of funds is the promise of new and affordable batteries with longer driving range, in other words, larger capacity. If one were to assess a return on investment by the US government and other US-based entities, private or public, we find that we have little to show for. There are no breakthrough materials on the horizon; there is little if no hope for a meaningful manufacturing base of batteries in the US - contrary to what the White House and ARPA-E would like us to believe; and there is a long list of US-based startup companies developing batteries and battery materials that are struggling against fierce competition from the Asia battery giants such as Samsung and LG Chem in Korea, and ATL, Lishen and several others in China.

Let's face it, the US cannot be a manufacturing base for batteries. Our cost structure is incompatible with the economic and financial constraints of battery manufacturing. Battery manufacturing requires billions in capital yet has to live on very thin profit margins. So let's stop investing our tax dollars in funding research in new battery materials so that Asian companies can then use the intellectual property for their own benefit (or purchase it for a dime on the dollar).

Instead, the US should focus its investments on system-level innovation. Tesla purchases batteries from Panasonic. These are similar batteries used in your notebook PC with a cost of about a buck or less each. Not an exciting business. Yet, Tesla integrates these batteries into a more complex system with far better margins - and far more difficult for Asia to copy. Tesla is only one example; the same concept applies to mobile devices, and industrial or grid-level energy storage.

© Qnovo, Inc. 2014 / @QNOVOcorp @nadimmaluf #QNOVOCorp    http://www.qnovo.com

Tuesday, September 23, 2014

8. YOUR BATTERY; YOUR ANXIETY.                                           

I love my electric vehicle, or EV, as we affectionately call our electric cars here in California. I love that it is quiet. I love its fast pickup from a stop. I love that it requires practically zero service: no oil change; no transmission service; no timing belts. Of course, I love too that it is eco-friendly and driving in the carpool lane. I am bullish on the future of electric vehicles, but first, the technology has to evolve a little more to give the consumer less anxiety, the topic of today's writing.

No, it is not a Tesla. It is not a Leaf. I am one of the early adopters of a Ford Focus Electric. It looks like a regular Ford Focus so it does not stand out in traffic. I nominally get about 80 miles of range which includes a lot of freeway driving...my normal daily commute. Slower driving in stop-and-go traffic increases my range to about 100 miles. Shave 10 or 15 miles during our mild California winters.

My vehicle is powered by a 24 kWh lithium-ion battery pack that is manufactured by LG Chemical, but in reality, only about 19 or 20 kWh are available to me. That's because to provide a 100,000-mile warranty, the battery has to reach 100,000 divided by 80 miles = 1,250 cycles minimum. So battery manufacturers and car makers choose to reduce the capacity of the battery to gain cycle life. Remember the whack-a-mole strategy from earlier posts. Using the water analogy, if you don't fill up the water bucket to the top, you can fill it more times over its life. Tesla Motors, Leaf and virtually every car maker employs this strategy. For the time being, it's ok, but that has to be addressed over time in order to make electric cars more affordable for the broad population.

When I first bought my car, my range anxiety was high. The car dashboard displayed how many miles of driving I had available in the tank, ehem, battery. I charged my car overnight, and I started my morning with about 80 miles. By the time I got to work, the dashboard showed less than 60 miles.  I was nervous every time my dashboard dropped below 50 miles, so I charged as frequently as I could. That's range anxiety. 

Now, nearly a year and half later, my behavior has changed drastically. I drive my car down to 10 or even 5 miles left in the battery. I plan my route. I know my destination and I know my return route. Keeping 50 or more miles for insurance does not make any more sense. I became comfortable with the given range of 80 miles and I use it effectively. I consistently get about 80 miles, and in the time since I bought it, my comfort level increased and my trust in my dashboard's range estimate has increased. Of course, my maximum driving range was still limited to the greater Bay Area. I cannot drive my car to, say, Los Angeles, but I do use nearly every mile available to me in battery.

However, my range anxiety got replaced with something else: Charging anxiety. You see, if I am comfortable taking my battery down to nearly zero, I need to know that I am close to a charging outlet when I stop. Good news here! The San Francisco Bay Area has lots of charging outlets. But the problem is the speed of charging. If my battery is near zero, it takes a whopping 20 hours to charge it at 120-Volt, and a mere 4 to 5 hours using the 240-Volt chargers. Ouch! That is not acceptable. That is at the core of anxiety in battery-powered cars, phones, or anything else. We need to charge them fast, and I mean really fast....As fast as filling up your gas tank at the gas station. 

If you look at what Tesla Motors is doing and what Elon Musk keeps advertising, none of it is about extending the range of their cars. Their publicized priorities are about building cars for the masses (in other words, lower price point) and secondly about charging their cars fast, in half an hour or so.  

Fast charging...we need it. Remember that!

© Qnovo, Inc. 2014 / @QNOVOcorp @nadimmaluf #QNOVOCorp    http://www.qnovo.com

Monday, September 22, 2014

7. I WANT AN HONEST DAY OF BATTERY USAGE.                                      

I talked about capacity, cycle life, tricks of the industry....today, I will distill it down to some simple thoughts for you to keep in mind when you are ready to select your next mobile device or smartphone. In particular, today's writing is about selecting a device with the proper battery capacity that can last you an honest day.

Mobile device manufacturers will give you an estimate of the battery life for their devices. For example, Apple's tech specs say that the battery on the iPhone 6 will give you up to 14 hours of talk time on 3G. Samsung's web page says that the Galaxy S5 will last up to 12 hours of internet use time on 4G. Plenty of independent sites on the web try to give a more objective analysis of the actual time a consumer can expect of their new device. Anandtech, for example, does their own thorough battery testing and provide a comparison of the battery performance of different devices. GSM Arena assigns a battery "Endurance rating." Think of it as an index meant to give you the user an understanding of the battery's ability to last.

Yet, the landscape remains confusing. What do the numbers mean in real life? Why is it that so many users can't reliably get a full day of use when these sites clearly claim a full day of use. Generally, predicting battery life has been difficult for the industry because the usage patterns of consumers vary wildly across the board. An employee with a desk job who uses their smartphone for limited personal use will see a very different performance relative to a traveling executive or salesperson who is constantly using their device.

Early cell phones had far smaller battery capacities (only about 600 or 700 mAh), yet they lasted an entire week if not longer. But these devices did not have too many features...only a radio transmitter-receiver to make phone calls. Today's mobile devices have multiple radios for the different frequencies and bands (2G, 3G, 4G, LTE...); they have beautiful but power-hogging displays with increasing resolution (meaning more power); they have GPS and navigation components that also need power from the battery; and worst of all, we, you, and all of us users, want to use them constantly in the day as we check emails, write texts and SMS messages, and check our favorite apps that want to access radio, displays, GPS, all simultaneously.

It is no surprise that the battery capacity in smartphones has grown massively since the introduction of the first iPhone to accommodate this extra demand for electrical power. From a battery capacity of about 900 mAh in 2007, most smartphones today have a battery capacity ranging between 2,500 mAh and 3,000 mAh for Android phones. iPhone 6 uses 1,810 mAh and its larger brother, the iPhone 6 Plus, packs more than 2,900 mAh of capacity.

For the most part, as experience and feedback from users have shown so far, smartphones with batteries closer to 3,000 mAh in capacity seem to provide their users with an honest full day of use (or more), even heavy users seem satisfied. So if you are shopping for a new smartphone, try to shoot for 3,000 mAh unless you know you are only a casual and occasional user in which case, about 1,800 to 2,000 mAh will likely be sufficient. Don't get too fooled by the marketing gimmicks.

So why can't we get smartphones with 4,000 mAh or even higher capacity? Trying to fit more than 3,000 mAh in a standard 5-in screen device is very difficult. Remember yesterday's writing and the whack-a-mole problem...if battery manufacturers increase the capacity, they will take a hit in cycle life or charge times. It is getting quite uncomfortable for them. So for the foreseeable future, expect smartphones to have batteries in the neighborhood of 3,000 mAh, but not much more than that, unless of course you are in the market for a huge 6-in phablet.

Tablets have it a little easier. They have a larger form factor and therefore can carry a larger battery -- 6,000 mAh up to 10,000 mAh. Most tablets on the market have a decent battery use time.

But wait, there is another problem. What if you forget to charge your smartphone's battery overnight? You wake up in the morning and realize your battery is down to 20% or less, and you need to run out the door to the office, school, or take your children to their school...As batteries have grown larger in size and the anxiety about getting a full day of use has dwindled, we are now beginning to face another problem, one of how long does it take to recharge the battery -- or refilling the tank.

If we use the car as an analogy, most vehicles manufactured today have a range between 300 and 400 miles (500 to 650 km). We, as a global society, seem to be content with that range. We don't complain to General Motors, Ford, Toyota, Mercedes, and the other car makers about the "limited range." That's because we know, implicitly, that if the tank is low on fuel, we are very often within reach of a refill station and, most importantly, we can refill our tank in a matter of minutes. This is the use model that mobile devices have to reach soon. We will soon expect our devices to last a full day of use, but also expect that our devices can be recharged substantially faster.

©© Qnovo, Inc. 2014 / @QNOVOcorp @nadimmaluf #QNOVOCorp    http://www.qnovo.com

Sunday, September 21, 2014

6. LIARS, LIARS AND BATTERY SUPPLIERS.                                                     

Several years back, as we were doing our initial fundraising round for Qnovo, lithium-ion batteries were the craze! A123 had just gone public at an insane valuation. Gas prices were through the roof and GM announced the all-exciting electric Chevy Volt. Tesla Motors had their Roadster and was promising the then new Model S. Promises of innovations that can make electric vehicles part of the mainstream were abound. Apple introduced the iPhone which for the first time in history had an embedded battery (one where the user could not remove). These were exciting times! With this background, you can then appreciate our surprise when one investor with ample experience in this space uttered a deep skepticism of the battery ecosystem. There seem to have been plenty of broken promises and certainly, as I learned later, opaque specifications that seemed difficult to verify. "There were liars, damned liars and battery suppliers," continues to resonate in my head, and after several years, seems to be more often true than not.

This blog is not meant to bash battery manufacturers. They do provide an immensely useful product and underlying technology that has proved very central to a mobile society. Not many of you remember the first mobile phones (not even smartphones) some 15 or 20 years ago when the battery, back then made of NiCd or NiMH, was the size of a brick....and it lasted too little. Rather, I want to use this blog to clarify who are the main manufacturers and what challenges they are facing.

There are over 6 billion lithium-ion batteries that are manufactured every year. Big numbers! Mobile devices account for nearly 75% of this volume. The rest go into electric vehicle and bicycles, camcorders, cameras and other items such as power tools. Less than 10 companies account for this worldwide volume. They tend to be large chemical conglomerates based in South Korea, Japan and China. Samsung SDI and LG Chemical are based in South Korea and are subsidiaries of Samsung and LG, respectively. In Japan, Panasonic, Sony Energy and Hitachi Maxell are the prominent ones. Panasonic is well known as the primary supplier of batteries to Tesla Motors. Then there are a number of fast-growing manufacturers out of China, primarily, Lishen, ATL, BAK and BYD. Lithium-ion batteries made in China tend to be of lower quality. They are widely used in China but mobile device manufacturers outside of China have generally preferred to use batteries manufactured by South Korean or Japanese companies. 

The US has a few small battery manufacturers that tend to be specialized, say for medical or aerospace applications. There are also several innovative and promising startup companies in the US that are pushing the envelope in terms of new materials, new designs and cost-effective ways to build batteries. 

Battery manufacturers face a slew of challenges, both technical and economical. First and foremost, batteries including lithium-ion batteries tend to be inexpensive. A battery in a typical smartphone costs in the neighborhood of $1 to $2. Profit margins in batteries tend to be very thin. Battery manufacturing is a very capital-intensive business. Safety concerns also plagued the industry in the past decade. Yet, it is a very competitive space, and the new Chinese manufacturers are only adding  increasing economic pressure on the established players.

Technically, the primary challenge is that battery manufacturers are not keeping up with the insatiable demand by the mobile and electronics industries. We hear of Moore's Law in electronics; it is driving the mobile industry. Moore's Law is the observation made by Gordon Moore at Intel in 1965 that electronics double in capacity every approximately 2 years. In contrast, batteries have doubled in capacity every 15 years!  This is a serious gap and growing problem.

Additionally, there is immense knowledge around electronics. High-tech companies have great talent around designing and manufacturing electronics with superb quality. In contrast, battery talent is limited. Companies that build mobile devices also have a great ability to understand electronic components and designs, yet surprisingly, many of them fall far behind in their knowledge of batteries. The result is that batteries and their specifications tend to be an obscure topic, and innovation in general has lagged. And to make matters worse, electronic and software engineers, the backbone of the mobile industry, simply don't like to deal with chemistry!

That is changing, gradually. It has to change. Batteries, their manufactures and the entire ecosystem needs to catch up to the operating standards and levels of innovation that the electronics and mobile industries have set forth.

© Qnovo, Inc. 2014 / @QNOVOcorp @nadimmaluf #QNOVOCorp    http://www.qnovo.com

Saturday, September 20, 2014

5. MORE ON DAMAGE AND CYCLE LIFE.                                                        

Damage in a battery happens. You can't stop it. It's part of the physics. Yes, it is possible to mitigate it. It is possible to postpone its onset. It is possible to reduce its impact (that's part of what our company Qnovo does)... But it's always there and we need to deal with it. Battery manufacturers have tended to sweep this issue under the rug but it is now coming back to bite them hard.

In technical terms, this damage inside the battery is referred to in terms of "cycle life." It is essentially a measure of how many times the battery can be charged and discharged before it is deemed dead. As I mentioned in the previous post, a battery is deemed dead when its maximum capacity reaches 80% of its original capacity as a fresh battery. So say a fresh battery has a maximum capacity of 2,500 mAh on its first day of use. After some number of charges and discharges, the internal damage reduces this maximum capacity. Eventually, this figure reaches 80% x 2,500 mAh = 2,000 mAh at which point it is officially deemed to be "dead", i.e., it needs to be replaced.

Why 80%? and not 75% or 63.1849%? Because experience has shown that shortly past the 80%-mark, the damage accelerates rapidly and the battery capacity plummets very quickly. Not good!

But now you are saying, "how can I know?" Well, welcome to the world of opacity in how battery makers specify their products. As a consumer, you don't know, nor you can measure it easily. Device makers tell you trust me, but you should not! All these apps that you can download from the Apple or Google stores also don't tell you anything. Right now, sadly, the only way you can tell that your battery is dead or dying is because it feels that it is dying. Your battery can't last you the day when only a few months earlier it did. Now to be sure, you also have to make sure that you don't have one or more rogue apps draining the battery in the background. So if you reset or even restore your mobile device and its battery is still not delivering, then it is a fairly strong hint that something is very wrong with the battery. If you are asking "why can't you fix it," the answer is "we can and we are." Let your mobile device manufacturer know that you are not happy if you suspect your battery cycle life is compromised.

Let's get back to cycle life. As you can see, cycle life and battery capacity are very closely tied together. Capacity is effectively the capacity that you get on your first day of operation, and cycle life is a measure of longevity of your battery's capacity. Cycle life is almost like the "Expiration Date" printed on a gallon of milk at the grocery store; except imagine that grocery stores decided one day to simply eliminate printing this crucial date. Grocery stores don't dare do it! Well, many mobile device manufacturers choose to hide or not disclose the cycle life -- effectively this expiration date of the battery is hidden. We are working on changing this behavior. But for now, I will give you some hints and tips on how to deal with this.

Most mobile devices including smartphones and tablets are rated to 500 cycles, i.e., you, the consumer, can expect to have 500 consecutive full charges and full discharges before your battery is deemed dead. Some devices do better than others. For example, older Apple iPhones lasted more than 500 cycles, whereas others either made 500 or fell shy of that figure. 

But some carriers (or operators are they are called outside the US), and in particular, Verizon Wireless, began demanding that mobile device manufacturers increase their cycle life specifications to 800 or more cycles, to effectively cover a 2-year warranty on the device. This new specification is beginning to proliferate but battery manufacturers are not happy! Increasing cycle life performance is not easy for them, and guess what, most of them are based in Asia and they don't like to ask for help!

So one of the tricks that manufacturers do to increase cycle life is to -- hold on to your seat -- increase charge times! Ouch! Now, you are becoming increasing familiar with the battery whack-a-mole strategy that battery manufacturers follow. You want more capacity, well, you may get worse cycle life...you want better cycle life, well, you will get worse charge times....and so on.

Fortunately, the technology to fix this whack-a-mole problem already exists...mobile device manufacturers have to deploy it more universally. For now, here are some hints -- albeit a little inconvenient -- that you can apply to extend the cycle life of your life battery:
  • Charge your device slowly using the USB port on your PC or notebook, not wall charger or AC adapter. This effectively limits the charging current to 500 mA. Yes, it is slow, but if you are not in a rush, it will help your battery.
  • Charge at room temperature! Not on your car dashboard in the middle of a hot sunny day, or worse yet, in the middle of a cold winter. Batteries hate being charged at temperature extremes, especially below 60 °F (or 15 °C), and above 95 °F (or 35 °C).
  • If you are not traveling or need your phone fully charged all day, then charge your battery to about 80 or 85% -- not to 100%. This will also help being gentle on the battery. 
More later.

© Qnovo, Inc. 2014 / @QNOVOcorp @nadimmaluf #QNOVOCorp    http://www.qnovo.com

Friday, September 19, 2014

4.  DID YOU SAY DAMAGE TO YOUR BATTERY?                                              

Yes, I did. That's when you wake up a few months after you make a proud investment in a new mobile device, then you realize that the battery is not lasting as long as you wanted.

Well, first to be safe, you have to make sure that you don't have too many apps running in the background draining the battery without your knowledge or your permission. But assuming that you already reset your phone, deleted the useless applications, and turned off all the background app refreshing, and you are still not getting the battery life that you had only a few weeks or months ago, then you are right, you are now experiencing the signs of battery damage, or in geek terms, it's called "capacity fade."

Remember when we talked earlier about the charge capacity of a battery and said it is measured in units of mAh. So let's say that you battery is rated at 2,500 mAh. So when your device is fully charged, and your fuel gauge in the upper right hand corner of your screen is reading 100%, it means that your battery is holding about 2,500 mAh of electrical charge...using the earlier analogy of the water bucket, it means the bucket is full and is holding some number of gallons of water.

But this assumes that the battery is new. As damage sets in the battery, its maximum capacity will actually degrade over time and use. This can happen for many reasons, such as poor manufacturing, extended exposure to low or high temperatures...etc. (we will get back to this at a later time). So the battery you have now has a maximum capacity of say 2,200 mAh instead of 2,500 mAh. In other words, you will notice a decrease in your battery life by about 1 to 2 hours per day.  

So now you are frowning, and possibly complaining: "But, but, but....the fuel gauge is still reading 100% when it is full." Yes, the fuel gauge only reads the available charge in the battery as a fraction of the maximum available capacity in the battery (it's a mouthful). In other words, on day one, your battery was able of holding 2,500 mAh, so 100% of the fuel gauge is then equal to 2,500 mAh. But after 6 months of use, the battery can only hold 2,200 mAh, and the 100% displayed by the fuel gauge is now equal to only 2,200 mAh. Ouch! 

If you are thinking about where you can read the lower battery capacity of 2,200 mAh, the answer is nowhere. You can't. The smartphone manufacturer and battery vendors either can't tell you or don't want to tell you. This is called "state of health" of the battery. 

When the battery capacity drops to 80% of its original capacity -- in our example here, it is 80% x 2,500 mAh = 2,000 mAh -- the battery is deemed dead and must be replaced. But as you gathered, it has been difficult if not nearly impossible for customers and consumers to prove that they have a dead battery. 

© Qnovo, Inc. 2014 / @QNOVOcorp @nadimmaluf #QNOVOCorp    http://www.qnovo.com

Thursday, September 18, 2014

3. SOME VERY FIRST, AND OBVIOUS, TIPS.                                                     

The most common complaint about the battery is that it "does not last." In other words, we have in our minds the expectation that our mobile device shall remain powered by this battery for an indefinite time...and when it's empty, it should recharge very quickly. We will revisit these concepts and solutions to them in subsequent blogs, but for now, I want to set, or rather reset, a few expectations.

First, remember to charge your better whenever you can. An empty battery is useless, and waiting 2 or 3 hours to charge your battery is very inconvenient if not annoying. Yes, you can carry one of these battery sleeves, but now you are carrying a brick, not a thin and stylish smartphone. 

If you can and have the time, charge your mobile device using the USB cable attached to one of the ports of your PC or notebook. Yes, it is slow, but it will recharge the battery as you are working on something else. If you are at your desk, you don't need the charging speed. And it's way better than getting to your car and realizing you are now down to 20% remaining charge.

If you don't sit at a desk, or you don't have a notebook or a PC, put a couple of standard wall chargers around your house, and give your device some charging whenever you can. Of course, try to remember to charge your device at night. There's no magic in this...it's just some simple discipline to start with. 

For an Apple mobile device, you can use the Apple wall chargers in addition to the USB port on a PC or Mac. Don't worry about using an iPad wall charger to charge an iPhone or vice-versa. An iPad wall charger will not charge an iPhone any faster (well, with the rumored exception of the iPhone 6 Plus). 

For an Android device, you can use a standard micro-USB wall charger (also known as AC adapter) as well as a USB port on your PC...it's your choice. If you try to use a tablet AC adapter to charge your smartphone, there is a small risk you may damage your smartphone battery. That's because if your smartphone is fairly new, say a year old or less, then the software inside your smartphone will protect it from drawing too much power and damaging its battery. But if you smartphone is older, then there is a risk it will draw more power from the larger tablet adapter and damage the battery.

One last tidbit...the difference between the wall charger of a tablet and a smartphone is the power rating, in other words, how much power the charger is capable of providing at its output. If you look at the standard AC adapter that comes with your smartphone (iPhone or Android or Windows), it will read typically "5V / 1.2A output".  This means that it is capable of providing a maximum current of 1.2 Amps at 5 Volts, or an equivalent output power of 5 x 1.2 = 6 Watts. Output here is the electrical power that flows through the USB cable to your mobile device.  In comparison, a tablet AC adapter will provide nearly twice that power or about 12 Watts. 

Finally, a car charger is very similar to your standard AC adapter. The difference is that the AC adapter takes 120V from your wall outlet and converts it to 5V that your mobile device can use. The car charger, by comparison, takes 12V from your car cigarette lighter outlet, and converts it to 5V.

© Qnovo, Inc. 2014 / @QNOVOcorp @nadimmaluf #QNOVOCorp    http://www.qnovo.com

Wednesday, September 17, 2014

2. WHAT'S THIS  mAh?                                                                                               

The lithium-ion rechargeable battery lives in many of our devices today, from our laptop PCs, to our tablets, and our smartphones, and many other devices that are not tethered to a power outlet. It has replaced the older generation of batteries such as nickel-metal-hydrides (also known with their abbreviation NiMH) and the more toxic nickel-cadmium (NiCd) batteries. You can still buy NiMH batteries at your local electronics store or Amazon: they are the size of the standard AA or AAA battery but can be recharged about a hundred times. They tend to be useful for your light torch or your children's toys, but they are not used any longer in mobile devices or other gizmos that require longer battery life.

The lithium-ion battery is today's king of the hill. It contains about 5 times more energy than the NiMH battery...in other words, it lasts 5 times longer. It comes in many different shapes; it can be a cylinder or it can be in a thin flat rectangular shape such as the one in your iPhone. It also requires proper care and operation. For example, if not properly charged in its appropriate wall charger, it may catch fire or worse yet, explode. 

lithium ion battery in iPhone 6
Lithium-ion battery in the iPhone 6
One of the key characteristics of a lithium-ion rechargeable battery is its maximum capacity to hold electrical charge. This is measured by the amount of electrical charge when fully charged, and is given in units of milliamp-hours, abbreviated as mAh. It is not a unit of energy. It is a unit of electrical charge. Higher numbers are better. More electrical charge means longer life and longer use time. Think of it as a bucket of water....capacity tells you the volume of your bucket. 

To convert from electrical charge to energy, one multiplies mAh by the battery voltage. Most lithium-ion batteries have a voltage of about 3.8 Volts (notice, this is way less than the typical 120 Volts out of your home outlet). So if we take the iPhone 6 battery, its capacity is 1,810 mAh (look at the bottom of the battery photo). When we multiply it by its voltage 3.82 Volts, then we get an energy of 6.91 Watt-hours (abbreviated as Wh). Once again, higher numbers are better.

So let me put this in perspective. One gallon of gasoline contains 34,000 (yes, thousand) Watt-hours. One gallon of gas has the equivalent energy of nearly 5,000 iPhone 6 batteries. So a takeaway here: You should appreciate why it has been difficult to make rechargeable batteries last for a very long long time.

Now, just because you have a bucket that has a given volume, it does not mean that you have that much volume of water in the bucket. First, you need to fill your bucket. That's exactly what "charging" does to the battery. It fills it with electrical charge. When the battery is fully charged, its battery meter reads 100%. That's the little gauge that shows up on the upper right hand side of your smartphone screen. Surprise, surprise, it is called the "fuel gauge." When you use your battery, the meter reading decreases until it gets to 0%. Presumably, your anxiety level has risen a lot before you reach the zero level.

Ok, now here's a little secret. Zero-percent reading of the fuel gauge is not really empty. It just means that you can no longer take charge out of the battery -- mostly for safety reasons. The electronic systems in your device are smart enough to say STOP and shut it down. So it's ok if you take your mobile battery to zero. It may be inconvenient to have an "empty" battery but it will not damage your lithium-ion battery. And no, there's no memory effect in lithium-ion batteries.

More later.

© Qnovo, Inc. 2014 / @QNOVOcorp @nadimmaluf #QNOVOCorp    http://www.qnovo.com

Tuesday, September 16, 2014

1. JUST A SIMPLE INTRODUCTION.                                                                     

If you are a consumer who has wondered why your lithium-ion battery in your mobile device fails your expectations, this blog is for you. If you are technically savvy but you are not a chemist, and often wondered how this lithium-ion battery works the way it does, then this blog is for you. If you are just curious about how to get more out of your lithium-ion battery, then again, this blog is for you. 

You have searched the internet for information on the battery inside your gizmo, how it works, how you should take care of it, what the fancy technical terms really mean, and what the manufacturer is promising you and what you are really obtaining....and I am sure you often felt frustrated because, well, little of it made sense to you. You are not alone. 

The fact is batteries have for a long time been a forgotten corner of technology. Before mobile devices became anchored in our daily lives, the battery meant that blackbox under the hood of our cars. Batteries did not evoke "clean" or "high-tech." We wanted a low-cost battery that cranked our engines even in the coldest days of winter.

Then came mobile devices, and now electrified vehicles... and things got more complicated. Everyone had an opinion, or a theory. "No, don't discharge to empty!" or "Beware, it has a memory effect." The fact is most of this advice is not based on real science and has little merits. True battery experts are hard to find...universities don't graduate enough of them, and they are in high demand.

This blog is intended to be read either as individually independent posts, or collectively as one continuous reading. The titles are summarized in the Table of Contents on the right hand side. Start with whichever topic you would like depending on your fluency level.

In the next post, we will start with the basics: What the terms really mean when one describes a battery.

© Qnovo, Inc. 2014 / @QNOVOcorp @nadimmaluf #QNOVOCorp