Posted by: iFixit.com
This is true for tablets and phones too: the lifespan of a battery is basically determined by the number of charge cycles and how “deep” those cycles are. Every dis/charge cycle damages the battery a little,and the deeper the charge cycle is, the more damage it does.
Contrary to probably everything you have been told, completely discharging then fully charging lithium batteries is the worst thing you can do to them (or any other rechargeable battery, actually). Also keeping your device cool significantly increases their lifespan.
All batteries wear out over time, but they don’t wear out at the same speed. Here’s how to keep your laptop battery running as long as you can: https://bit.ly/3E4asPJ