Pretty much everything degrades lithium ion battery performance. Charging, discharging, being fully charged, being too hot, being thought about too much or too

Pretty much everything degrades lithium ion battery performance. Charging, discharging, being fully charged, being too hot, being thought about too much or too little, etc. If it's plugged in, it's probably hot (running in full-power mode) and fully charged... this kills the battery.