I know that charging the battery too fast can overheat the battery and shorten battery life. But is charging it slowly, e.g. from a USB 2.0 cable plugged to a laptop, also harmful for the battery? I know there is a 'USB charging mode' designed for this, but I am not so sure if it is bad for the battery.
I have Googled, but most links are forums where people offer their opinions and personal experiences, I want to know whether someone has actually tested this out?