What Happens If Laptop Battery Is Overcharged. There are three main things that affect the lifespan of a laptop battery. In short the answer is a big NO.
Every laptop today uses a Li-ion battery. Damage to the battery from overcharging would only occur in the very unlikely event of a malfunction of the charging system. The exteriors of the batteries become too hot to touch and the battery might melt or swell up and leakage may occur.
If you are referring to a car.
The circuity that controls the charging in in the battery so its possible that this circuity can fail and cause problems. If you are referring to a car. True that it is best to fully charge then fully discharge. Normally the battery will not overcharge.
