I thought the more important thing was not to discharge your battery too deeply. It's especially bad to keep it at a very low state of charge for a long time (u

I thought the more important thing was not to discharge your battery too deeply. It's especially bad to keep it at a very low state of charge for a long time (use the device until it dies and then not recharge it for a day or two). If you try to keep your battery charged to above 40%, its lifetime should be a lot longer. I also don't charge my ThinkPad to 100% (I limited it to 85% using tlp), but afaik that's not as important. My iPhone 7 is now a little over two years old, and battery health reports that the maximum capacity is 90%. I use around 60% of charge every day, but I can count the number of times it went below 20% on my fingers.