Charging Li-ion powerbanks

Since my region has had problematic power outages recently, I’m thinking about rechargeable batteries and powerbanks;

It’s generally accepted that rechargeable batteries for modern consumer electronics¹ degrade faster if they’re frequently charged to 100% of nominal capacity. Indeed, so much so that battery manufacturers specify lifespan in terms of the number of cycles to reach 80% of the rated battery capacity. In addition, “Simply storing lithium-ion batteries in the charged state also reduces their capacity”.

And that’s why various operating systems, both general purpose OSen such as linux/macos and more specialty OSen (Android, EV, other embedded systems), support limiting charge to less than full capacity.

But I have quite a few rechargeable batteries that do not support that functionality. Off the top of my head, I can think of many in my home, two powerbanks (the sort that are marketed for recharging mobile phones), an amp for my cello/bass guitar, an ebook reader, a shop light, multiple headsets/headphones/earbuds, a toothbrush, a shaver, a couple camping lanterns, and piles (ha, multi-language pun!) of rechargeable AAs/AAAs. I suspect that (a) there are more and (b) that this is not way out of line for middle income households in the US.

Scheduled Charging

So how about putting the less-frequently used devices to be charged on a schedule? Many modern power strips come with USB-A and USB-C ports and I can plug the power strip itself into a smart plug that only turns on for a few hours per day? or even per week?

Would that extend the life of these batteries? Without the disadvantage of having insufficiently charged devices when I want to use them?

See Also/References

• Wikipedia on Lithium-ion batteries