Well it depends what you're doing with it. In my case my CPU is averaging about 1% with the odd burst here and there. As a precaution I propped it up to allow i

Well it depends what you're doing with it. In my case my CPU is averaging about 1% with the odd burst here and there. As a precaution I propped it up to allow increased airflow underneath. You do have a point in that certain devices can suffer from overcharging and bulging batteries. This issue is largely addressed in newer devices. I can see that the BMS in my laptop server is holding at 90% charge. Definitely worth checking if you plan to use an old phone/laptop/tablet as a 24/7 device.