Many years ago, the Samsung Galaxy Note 7 gained notoriety when its batteries caught fire in a series of incidents. Since then, there has been a steady stream of similar, albeit isolated, incidents. However, despite the high-profile media coverage of batteries gone bad, the vast majority of Li-ion batteries are safe.
The chemical reaction that occurs inside a lithium-ion cell is complex, but like any battery, there is a negative electrode and a positive electrode. In lithium batteries, the negative is a lithium-carbon compound and the positive is cobalt oxide (although many battery manufacturers are moving away from cobalt). These two compounds cause a safe reaction when controlled and provide energy to your devices. However, when the reaction gets out of control, you end up with headphones melting in your ears. What changes a safe reaction to an uncontrolled reaction can be any number of things: excessive heat, physical damage during use, physical damage during manufacturing, or using a bad charger.
The three basic rules that have kept me safe (so far) while testing dozens and dozens of batteries are:
- Avoid cheap cords, chargers and plug adapters.
- Make sure the batteries are not exposed to excessive heat (over 110 degrees Fahrenheit).
- Inspect batteries regularly for signs of damage.
The most important thing is to avoid cheap wall outlet adapters, cords, and chargers. This is the most likely source of your problems. Those chargers you see on Amazon for $20 less than the competition? It’s not worth it. They likely drove prices down by skimping on insulation, leaving out energy management tools, and ignoring the basics of electrical safety. Price alone is no guarantee of safety either. Buy from reputable companies and brands.
And then there’s the heat. Too much can cause all kinds of problems, both in terms of rejection and in terms of safety. Avoid heat and take care of your batteries while they are charging. If your device gets too hot while charging, it could be a sign of problems. Likewise, be wary of swollen, bulging, or deformed batteries.
