Mobile devices

02Jul 2020

Tesla’s market valuation hit today $225 Billion, more than the valuation of any other auto manufacturer, highlighting the importance of the lithium-ion battery to our economies.

The battery is the product differentiator for electric vehicles, stationary energy storage and many consumer devices. Each category is pushing the specifications of the battery — and they all share similar themes: more charge capacity, faster charging, battery longevity, less weight, less cost, and absolute safety!

Many manufacturers shy away from sharing lessons learned from deploying batteries in large volume. In some respect, it is understandable — the battery is a competitive advantage. But by keeping opaque, the end user suffers. At Qnovo, our customers have deployed our battery management solutions on well over 100 million smartphones. Along the way, we learned a few important things. I will share here two relevant observations:

1. Optimizing between performance, cost and safety needs smart software: 

Innovation in materials is important but increasingly insufficient to give end users the experience they deserve. The battery has grown from nearly 1,500 mAh in early smartphone models (the original iPhone’s battery capacity was 1,400 mAh) to a whopping 5,000 mAh in 2020 models to accommodate 5G networks. With the increase in capacity and energy density comes a slew of design headaches leaving little margin for error: maintain the battery’s longevity; provide fast charging; minimize battery swelling, all at once. Optimizing between strict performance specifications, pressure to source from lower cost battery manufacturers in China, and absolute safety is no longer exclusively in the realm of materials. Instead it demands battery intelligence and smart software.

Similarly, electric vehicles are under similar if not tighter constraints. Longer driving range, faster charging, exposure to extreme temperatures, presence of minute manufacturing defects, and immense cost pressures make battery design a difficult task. It is no surprise that auto OEMs now rank battery intelligence software as critical to their systems. OEMs are also becoming more involved in the design and manufacturing of batteries. For instance, Apple designs its own batteries in Cupertino, and BMW invested €200 million in a battery cell competence center in Munich.

So what can intelligent battery management software do? Here’s one representative data point from our results. Our average longevity over 100 million smartphones shipping with our solutions is 1,900 cycles at 25 °C, and an incredible 1,300 cycles at the punishing temperature of 45 °C. Otherwise, an average smartphone will last between 500 and 1,000 cycles. Increasing longevity raises the available capacity and use time, improves the battery’s health and safety, reduces its swelling to make thin smartphones, and gives the end user a far better overall battery experience. 

2. Improvement in safety requires more predictive smart software:

The cell voltage rose from a safe 4.2V in early smartphone models to 4.47V in the newest 5G models — needed to add more energy to the battery. At these high voltages, the margin of safety is razor thin: battery swelling, extreme temperatures, user abuse, minute manufacturing defects, fast charging all contribute to an elevated risk of battery failure or fire!

Data from the field indicate that unsafe battery failures account for 10 to 20 incidents per million devices (measured as parts per million, or ppm) — these incidents lead to property damage or personal injury to the user. Any industry with failure rates in ppm can laud its accomplishments; but ppm levels are grossly inadequate for batteries. There are approximately 1.5 billion new smartphones sold worldwide every year. At ten ppm, there are 15,000 unsafe smartphone incidents annually! This is not acceptable. 

It is incorrect to assume that the industry can improve battery failure rates solely by tightening battery manufacturing processes. It is true that battery manufacturing defects contribute to failure — but defects are not the only reason why a battery may catch fire. Improper operation, poor smartphone design and specifications, and user abuse can all lead to premature unsafe failure. Battery manufacturers, especially in China, are also reluctant to add more controls and cost to their manufacturing processes — battery manufacturing remains an industry with thin financial profits at best, or more often endemic losses.

Let’s step back for a moment and briefly examine a different industry: lens making. Historically, making high quality lenses for photography was a specialty left to a few companies in Germany and Japan, e.g., Leica, Nikon or Canon. They excelled at their manufacturing prowess and accuracy. Then innovation struck in the form of cameras embedded in smartphones. These used cheap plastic lenses but corrected for their optical deficiencies using software. Images from modern smartphone cameras can surpass the quality of those from expensive DSLR cameras. The camera  industry showed that it can substitute manufacturing accuracy with computation, the latter being enormously less costly.

We use a similar philosophy to improve the safety of batteries. We recognize that manufacturing defects are part of building batteries. We use predictive algorithms to identify these defects long before they become a safety hazard, then manage the operation of the battery to reduce the risk of a failure. The result is that there were zero unsafe failures over 100 million smartphones in the field. 

31Mar 2020

While the current situation has put us all in unfamiliar territory, one bright spot has been the willingness of so many people and organizations to offer advice and assistance. With hundreds of millions of us isolated in our homes, making especially intensive and important use of our phones and computers, it seems like an opportune moment to share four battery-specific recommendations that can help ensure your personal safety and extend the lifespans of all our devices as we adjust to this period of uncertainty, and WFH normalcy.

First, and most imperatively in the near term, never ignore a battery that is swelling. This can happen over the course of just a few days, especially in aging devices, and is a sign of internal failure that can put you and your family at risk of fire or injury. If your phone starts bulging or separating, even slightly, or your laptop or tablet won’t sit flat, its battery is likely swelling. In this case, stop using the device immediately and contact its manufacturer for help. Second, watch out for heat. If the backside of your phone gets uncomfortably hot while it’s charging, that’s a warning sign, and once again time to contact the device manufacturer. More broadly, avoid placing devices in high-heat situations, especially when charging. The classic case is of a ride-share driver, with their windshield-mounted phone continuously charging while baking in direct sun, but it can also occur at home if your phone is charging on a sunny windowsill, above a radiator, or nestled into a blanket. The combination of an elevated charge situation and high ambient heat may increase the risk of a fire and is certain to degrade a battery’s health prematurely. More detail about heat and batteries can be found here.

Third, be especially careful with aftermarket batteries and chargers, even ones that carry a familiar brand name, because counterfeiting has become more and more common, and incentives to do so will only increase during a global emergency. This is a good reason to extend the life of your original batteries for as long as possible. While it can be annoying when smartphone manufacturers restrict users and unauthorized repair shops from doing battery replacements, it’s done in part because there’s ample evidence that fake replica batteries have a much higher risk of fire than authentic ones, and because the replacement process is often not straightforward. Likewise, cheap chargers can create overheating by delivering too much current, which can create a similar fire risk for your batteries.

Finally, extending the lifespan of our phones, laptops, tablets, and other daily-use devices will take on extra importance, especially with phone prices creeping into four digits. In my experience, preserving battery health is the single best way of doing this. I wrote some time ago about basic strategies; here are some updated recommendations to consider:

  • Avoid “fast-charge” approaches and use the lowest amount of charging current possible. Although it takes longer, charging your phone from a computer using a USB cable is much gentler on the internals of the battery. (Note that this principle also applies to electric vehicles – super-fast charging stations are hard on your vehicle battery.)
  • Avoid charging your phone overnight, because it’s better to not keep the battery at 100 percent charge for extended periods. I aim to keep my charge levels between 25 and 85 percent unless I’m traveling, and my year-old smartphone battery health has not degraded at all.
  • Per the previous point, Apple’s iOS operating system offers battery health monitoring, and in the newest version(13.0)  the option of “Optimized Battery Charging,” which learns your daily charging routine. This is worthwhile, and we’re starting to see other manufacturers and even mobile operators become more attuned to this type of functionality, particularly in Asia.

We all have plenty to worry about in these unusual times; hopefully these bits of advice will help prevent battery-related problems from adding to your load.

30Dec 2019






2. Batteries will deliver better performance but with optimized compromises:







4. Batteries will become safer in the field:





19Aug 2019


Why it matters: Smartphone manufacturers and Apple say that their actions guarantee the integrity and safety of the batteries by preventing the possible use of counterfeit batteries. Some users have objected citing a right to repair.

Users perceive batteries as consumable:

  • Historically, smartphones had externally removable batteries.
  • After the introduction of the iPhone, all smartphone OEMs followed Apple by making the battery non-removable.
  • This design change was necessary to make smartphones thin and light.
  • Batteries are sophisticated components inside a precision-engineered smartphone. Much like other internal components, such as memory or display, they are increasingly difficult and expensive to replace. 
  • A botched battery replacement can lead to a fire.
  • The historical perception of batteries as consumables is no longer true. 

Why fake batteries are a real problem: 

  • Fake replica batteries are inexpensive counterfeits largely from China, made by manufacturers with limited control on quality.
  • Statistics show that counterfeit batteries have a much higher prevalence of fires than authentic batteries.
  • Detecting counterfeit batteries is not easy without the use of battery intelligence.

Why smartphone OEMs do not sell batteries:

  • Replacing the battery inside a smartphone is a complex operation with risk of damage to the battery. 
  • Recall the Samsung Note 7 fires were connected to the mechanical sizing of the battery inside the smartphone causing a mechanical dent in the battery.
  • To be safe, smartphone manufacturers direct users to qualified repair shops.

What smartphone owners can do:

  • Take actions to ensure that your battery outlasts the rest of your smartphone. Avoid super fast charging if you can. Avoid charging overnight to 100%. Avoid hot temperatures.
  • If you ever have to get your battery replaced, get it done at an authorized repair shop where the battery can be traced to a trusted manufacturing source.
19Feb 2019

Some time in August of 2013, hackers breached Yahoo! servers and stole private account information for up to 3 billion users. Verizon Communications received a $350 million discount in the price of its acquisition of Yahoo! in 2017, exemplifying the staggering costs of one single encounter with cyber risk.

The concept of risk and risk management is not new. In 1688, Edward Lloyd set up what would become today Lloyd’s of London to contain the emerging risks of the new and growing maritime trans-Atlantic trade. Since then, the business world has worked diligently to contain such risk in everything from food to the Internet.

Actually, almost everything. One such modern risk that remains inadequately addressed is battery safety, specifically the safety of lithium-ion batteries that are so ubiquitous. To be fair, industry has recognized long time ago the safety hazards surrounding the lithium-ion battery. Battery fires in the early 2000s caused expensive recalls. But they were largely treated as one-off events. These were times when the annual volume of batteries was a few hundred millions. These fires were not treated as an on-going risk. They were seen as failures in manufacturing that could be eliminated by improvements in factories or designs.

Today’s battery shipments have skyrocketed to billions of units and counting. Even a minuscule chance of battery fire becomes a real problem when multiplied by the sheer volume of batteries. Battery failures are an ongoing risk that needs to be contained.

Estimates place the risk of battery fire in the range of a few to tens of parts-per-million (or ppm). One ppm means that for every one million units shipped, there is a risk that one of them will catch fire. It does not mean that one *will* catch fire. It just means that statistically speaking, the probability of a fire is one in a million. Now that seems like a small number. You might tell a precious love that they are “one in a million.” In an industry that ships two billion smartphones annually, that translates to several thousand battery fires annually! Not acceptable! We need to bring this figure down by a factor of 100 or 1,000.

Edward Lloyd’s business was possible because it had its underpinnings in the mathematical advances of probability pioneered by Blaise Pascal and Pierre de Fermat early in the 17th century. In that same vein it is possible to make great improvements in battery safety because it leverages the advances in computation of the past 50 years.

Every smartphone is a miracle device. It contains a processor that is infinitely more powerful than the computer that landed Apollo 11 on the moon. It also contains sophisticated electronics that can measure minute voltages and currents, and in turn it is very telling of the chemical reactions inside the battery. Merge it all with intelligent software, and we can now predict what the battery’s health will be in the future.

But why can’t we just manufacture the perfect battery that will never catch fire? Simply put, it is prohibitively expensive. Consider this: nearly every person with a smartphone is also an amateur photographer. Despite the fact their camera lens is optically deficient, software allows them to take incredible photographs.

The same goes for batteries. Manufacturing batteries in large volumes means that some will have defects. That’s just the balance between quality and cost when it comes to battery manufacturing in large scale. To make matters more challenging, every person will use or abuse their battery in unpredictable ways. It becomes essential to catch and screen these few bad batteries in the field before they become a hazard. Naturally, this is not meant to supersede good manufacturing practices, but rather to complement them in our quest to reduce battery fires to zero.

So how does it work? I talked in the past about electrochemical impedance spectroscopy (EIS). It is a workhorse test instrument in battery laboratories around the world. It is capable of measuring the chemical processes that are taking place inside the battery. Now imagine if you had such a similar tool inside your device. With some expertise, you can now start making smart decisions about your battery. This is not a new concept; a similar concept, for instance, allows glucose measuring devices to save the lives of millions of diabetics.

It’s high time we get serious about battery health and safety. Let’s address this risk before it escalates. The spread between device capabilities and battery threats is only growing — let’s get smart and manage potential incidents before they blow up into something bigger.