Why are Batteries Blowing Up?

By Michael GrossmanDecember 14, 2015Reading Time: 6 minutes

If you have caught the news lately you may have noticed an increase in stories about fires being started by electronic devices. Everything from battery powered cars, toys, cell phones, laptops, to electronic cigarettes seem to be catching fire, exploding, or in some way injuring people. While it is easy to find these stories, most of them lack proper context. These fires are a statistically tiny, but very real danger inherent in the lithium ion batteries that power nearly every mobile device we use today. While incidents of battery failure are exceptionally rare, the sheer quantity of devices using lithium ion batteries means that incidents are bound to happen. Sadly, in our opinion the media has hardly done an adequate job explaining the risks to the public that lithium ion batteries present.

When a lithium ion battery incident occurs, the rather shocking fires or explosions, which result from failed devices, are sure to draw media attention. However, in most of the stories that are really about lithium ion battery failure, the media instead chooses to focus on the product that contained the batteries. As a result you get headlines like "cell phone catches fire," "laptop burns down house," or even "electronic cigarette explodes." In each of the instances the media is reporting the effect, but not the cause. In a story I came across while researching this article, a man's bedroom caught fire as the result of a failure in his laptop's lithium ion battery. However, nowhere in the story did the reporter mention the batteries. It did however contain a mention that the local fire department "is warning the public about the dangers." One has to wonder how effective a warning can be when you do not identify, by name, the danger.

Without mentioning lithium ion batteries, let alone explaining the problem, stories about these accidents are not informative, only sensational. While the risk people face from lithium ion batteries truly is negligible in terms of the overall reliability and safety of the batteries, the fact that there are so many batteries, in so many devices, means that some people will experience incidents like the fires and explosions we see in the news. While one cannot overemphasize just how safe lithium ion batteries are, they can be made safer when properly handled. From a survey of the news and relevant scientific literature, one can see that the biggest causes of catastrophic lithium ion battery failures are excessive heat in the environment, improper charging, and physical damage to the batteries.

Lithium ion batteries can be sensitive to heat. This is one of the reasons iPhones have a warning that pops up when they are too warm to be used safely. If lithium ion batteries are heated enough, a process known as thermal runaway can occur. Depending on the materials used in a particular lithium ion battery, the threshold for thermal runaway will vary. While in some cases thermal runaway will cause a battery to devour itself over the course of a couple of hours, in more extreme cases the temperature of the battery can rise several hundred C° in a matter of seconds. In this scenario you get a sparkler/blow-torch type of fire described by many witnesses. If the casing surround the lithium ion battery lacks proper ventilation, the sudden build-up of gasses can cause an explosion. Pretty scary, but rather infrequently occurring stuff. So to avoid some heat-related incidents, these batteries should never been kept near a heat source, or exposed to direct sunlight for prolonged periods of time.

Perhaps the most overlooked issue with lithium ion batteries is charging. Unlike throw-away batteries which come in standard interchangeable units, like AA, AAA, C, D, 9-volts, etc., many lithium ion batteries are designed for a specific product. This means that they also come with specific chargers for that product's particular battery. While this was not an issue when each device came with its own clunky charger and you were left to figure out which charger went with which device, the marriage of chargers and devices other than the device they were made for can have unintended consequences.

Because of the risks inherent in charging lithium ion batteries, they should never be charged except when you are nearby. While this cannot prevent a problem from occurring, it can mean that you are in the best position possible to mitigate any damage that may result from an incident. This means not charging devices while you sleep. I know a lot of folks like to charge their phones while they are sleeping. Given the low failure rate of lithium ion batteries, there is nothing inherently dangerous about this, but it is not the safest situation either. While it may be a minor inconvenience to have to be nearby when a device is charging, it could potentially prevent both serious injuries and property damage.

Of course, the most obvious source of battery fires are damaged batteries. Punctures in the batteries or even heavy blows can cause them to become unstable. This generally results in a fire, not and explosion. If you suspect your battery has been damaged in any way, be it through a fall, getting it wet, or through some other means, you should get a replacement and discard the damaged battery.

One last area of concern, not mentioned by most of the sources is defective manufacturing. While this is not as big a concern for products such as laptops and cell phones (although through the years they have had their share of recalls), anything that requires you assemble a system, powered by a lithium ion battery, without instruction from a manufacturer should cause you some concern. A common way that arises is when building electronic cigarettes (e-cigs) from scratch. There are many do-it-yourself kits on the market, but the consequences for someone getting it wrong can be significant. When building a custom e-cig, it is pretty common for the consumer to pick out their own battery. Many times consumers opt for the cheapest option on the market, since they think "batteries are batteries." Unfortunately, lithium ion batteries are one technology where you really get what you pay for. There are numerous batteries in the marketplace, which while cheaper, use outdated and substandard materials. These materials tend to fail at much lower temperatures than comparable batteries found in devices like your cell phone or other similar devices. This may partially explain some of the recent surge in e-cig related injuries. While these incidents are still uncommon, the proximity of a lithium ion battery to the user's head and neck means that such failures often result in serious injuries. If you are building your own lithium ion powered device from scratch, it is best to thoroughly research the process before hand and not try to save a few bucks on a battery.

While lithium ion batteries are becoming safer due to better materials and better manufacturing techniques, perhaps the most exciting safety features to come down the line are protection circuit modules (PCM). These devices are small chips incorporated into lithium ion batteries that monitor temperature and battery output. When the temperature begins to rise, PCM are capable of cutting off the power flow within the battery and avoiding thermal runaway. While they are not foolproof, coupled with good handling by the owner, PCM are capable of making relatively safe batteries even safer. When purchasing a cell phone or other lithium ion battery powered device, it can help to take a moment to research whether your product is equipped with some type of PCM.

Finally, now that we've discussed all of the instances of user error and freak accidents, we must also consider the possibility of improper design and negligent manufacturing. Though the manufacturers of the world would like you to believe that user error is always the cause of such problems, it simply isn't true. Especially in the realm of inexpensive electronics, substandard products and components can and do make it to market. If an injury is caused by a defective battery, products liability law holds that the manufacturer is likely to be held financially responsible, unless, of course, it can shown that the consumer did something improper with the device. Aside from that, and notwithstanding the particular cause of failure (e.g. negligent manufacturing, improper design, defective marketing, etc.), manufacturers are usually legally liable for injuries and property damage caused by defective batteries. When such an event occurs, you'll need the help of an attorney who can handle a defective battery claim to hold the manufacturer accountable.

While it is regrettable that injuries from lithium ion batteries seem to be on the rise, it might be more lamentable that the media at large has done such a poor job of explaining the danger to folks. In a nutshell, you can greatly reduce your by following a few simple steps:

  • Make sure that batteries and devices are kept away from heat sources, including prolonged sunlight.
  • Never use chargers that are not intended for a particular device.
  • Never leave charging devices unattended.
  • Immediately replace damaged or possibly damaged batteries.
  • When constructing devices from scratch, avoid low-quality lithium ion batteries.
  • Shop for devices that have protection circuit modules (PCMs).

By following these steps you can you maximize the safety of your lithium ion batteries, while minimizing the potential for accidents. Those accidents that do occur will hopefully be caught sooner and result in less severe injuries. However, given the number of variables and the technical detail involved in these accidents, should one occur and injure a loved one, it is absolutely imperative that you make sure that a thorough, professional, and timely investigation is undertaken. The technologies we enjoy are not going anywhere, so in the end the best we can do is make sure that we do what we can to enjoy them safely.