Have you ever fully charged your cell phone only to realize that a few minutes later, the battery dropped 5 or 10 percent before you even used it? No matter how much of an effort you make to treat your phone well and conserve your battery, it doesn’t always make a difference – have you ever wondered why?
Compared to older phones, smartphones have a significantly shorter battery life. Sounds counterintuitive, since new technology should logically improve batteries – but we demand a lot more of our mobile devices than we ever have in the past. Background applications, large screens, and 4G networks all demand a lot of juice.
Lithium Ion vs Lithium Polymer Batteries
That still doesn’t account for the 10% drop you see as soon as you unplug your phone – however, it’s completely normal. Everyone has heard that leaving your phone plugged in too long will corrode the battery and shorten its lifespan. That was true with older phones that used lithium ion batteries, but newer phones use lithium polymer batteries. Lithium polymer batteries last longer in general, and they are engineered so it is impossible to overcharge them. When you charge your smartphone and the battery reaches its maximum capacity, it will cut off from the power source and run on its stored power. After a certain point, the wall power will kick back in and the cycle will continue. This feature is great because it means the battery will lose less capacity over time, but it also means each cycle is shorter.
Apple was the first mainstream device to use lithium polymer batteries, and most other phones have followed suit. However, some older phones still use lithium ion – so if you are worried about overcharging your phone, check your user manual to know which battery your phone uses.