Battery draining with external power while under load?

[JasonG-FR]

Quick question as we're here, what bash command returns the charging state. I'm used to using acpi -V (when using SuSE) but for now I'll stick with the supplied Manjaro and acpi does return something, but doesn't seem to read the charge state (instead it tells me I have a 0% charge). Is there an other command I should use? acpi wasn't installed by default so I get that Manjaro or Pine64 may prefer to use something else.

You can use this command to get the remaining capacity :

Code:

cat /sys/class/power_supply/cw2015-battery/capacity

Question I now have, is this an issue for the battery health to not ever be charged fully? I think even with this battery charged up to 92% I'd probably be happy with the mileage it goes but I don't want it to cause excessive wear. I'm no expert in electronics (or anything computer related, probably) but I've read somewhere that it is actually the stages near full discharge and fully charged (where it constantly stops and starts charging) which cause most wear. But yeah, I would appreciate some expert views on this.

A lithium cell suffers from being fully discharged and fully recharged, which means that you'll get more cycles from your battery if you keep its capacity between 5% to 80% than if you charge it from 5% to 100%. Actually it has been estimated that you gain around 200% of battery lifespan if you only charge it to 80% instead of 100%. This is why trickle charging (constantly charging / discharging near 100%) is so damaging to batteries. That being said, it's not a big issue to charge it to 100% once in a while (it can even help to re-calibrate the battery and improve the capacity reading) or when you actually need the extra 20%.

Here are some studies if you want to have expert views:

Factors that affect cycle-life and possible degradation mechanisms of a Li-ion cell based on LiCoO2, https://doi.org/10.1016/S0378-7753(02)00305-1
Study of life evaluation methods for Li-ion batteries for backup applications, https://doi.org/10.1016/S0378-7753(03)00208-8