[Feature Request] Allow to set battery charging limit

• /e/ version: 1.19
• Device model(s): FP5, but may apply to other devices

Summary

As explained in this Ifixit blog post, it is best to not charge your phone above 80% to preserve its battery. If it isn't as much of a ploblem with a device like the FP5 (which has a replaceable battery), it is for most of the phone supported by /e/os. The official FP5 image has this option, as such it should be quite easy to develop as it already prove it is doable. Multiple open-source apps does the same, but all of them requires a rooted device.

Description

What is the current behavior?

No such option is available. Phone won't stop charging until it is at 100%

What is the improved behavior?

In the settings, an option allows to set a limit to 80% (or any other custom percentages) of the nominal capacity.

What does it bring?

The ability to set max charging to a level that preserve the battery (80%).

Validation

• On a device which battery is bellow 80%, Set limit to 80% , then charge it -> It should stop charging around upper 80% (like 80.95%), and not start charging again before it reach around 79% (like 80.05%).

Previous issue : #5879 (closed)