Some phones now have an option to limit charging to 80%. That should eliminate the problem entirely. If your phone won't do that, you can use a smart power sw

Some phones now have an option to limit charging to 80%. That should eliminate the problem entirely. If your phone won't do that, you can use a smart power switch. Some mentioned to simply have it on a timer, but if you wanted to get fancier, you could use IFTTT to toggle it on/off based on battery percentage. I'd likely make it turn on at 40% battery and off at 60%.