Does frequently shallow charging speed the aging of Li-ion batteries?

XTAR Light

Apr 26, 2010
Shallow charging can actually help prolong the life of Li-ion batteries by reducing the stress on the battery. For example, unplugging after charging a Li-ion battery from 40% to 80% doesn't speed up the aging of the battery. On the contrary, charging the Li-ion battery when it's fully discharged, or overcharging it, this will accelerate irreversible capacity loss and damage to the battery.

A charging cycle is a full charge and discharge of a rechargeable battery. Plugging and unplugging the battery once doesn't mean one cycle. If a Li-ion battery has a lifespan of 300 to 500 charging cycles, assume that a full discharge can give Q capacity. Without considering the capacity decline after every charging cycle, the battery can deliver 300Q-500Q power in total over their lifetime. If you use half of the capacity each time, you can charge 600 to 1000 times. And using 1/3 capacity each time, then you can charge 900 to 1500 times. So the life of a Li-ion battery is proportional to the battery's overall charge, not to the number of charges.

The Li-ion batteries can benefit more from shallow discharge and shallow charging. And they shouldn't be totally depleted and deep cycling frequently. If you don't use a Li-ion battery for a long time, to store them better, pls make sure it has some charge, ideally 50% to 60%, before putting it away. Then the battery will last longer.


Flashlight Enthusiast
Apr 19, 2005
well that is why ev manufacturers use 40-80 cycle, it does add thousands of cycles to batteries lifespan.