Many years ago, the Samsung Galaxy Note 7 became famous when its batteries caught fire in a series of incidents. There have been a series of similar, albeit separate, incidents since then. However, despite the high profile coverage of faulty batteries, most Li-ion batteries are safe.
The chemical reactions that take place inside a lithium-ion cell are complex, but as with any battery, there is a negative and a positive electrode. In lithium batteries, the negative is the lithium-carbon compound, and the positive is cobalt oxide (although most battery makers start from cobalt). These two compounds cause a safe reaction when controlled and bring power to your devices. If the reaction gets out of control, you end up with earbuds melting in your ears. What turns a safe reaction into an uncontrolled reaction can be any number of things: excessive heat, physical injury during use, physical injury during manufacturing, or using the wrong charger.
The three basic rules that have kept me safe (so far) with testing lots and lots of batteries are:
- Avoid cheap cables, chargers, and adapters.
- Make sure the batteries are not exposed to excessive heat (over 110 degrees Fahrenheit).
- Inspect batteries regularly for signs of damage.
Avoiding cheap wall adapters, cables, and chargers is very important. These are your potential source of problems. Those chargers you saw on Amazon for $20 cheaper than the competition? It’s not worth it. They may have gotten the price down by skimping on insulation, leaving out energy management tools, and ignoring electrical safety basics. Price alone is no guarantee of safety, either. Buy from reputable companies and brands.
Then it’s hot. Their abundance can cause all kinds of problems, both in terms of egress and safety. Avoid heat, and take care of your batteries when charging. If your device gets very hot when charging, this could be a sign of problems. Similarly, be aware of any swollen, cracked, or malformed batteries.