 You don't need to be an 'investor' to invest in Singletrack: 6 days left: 95% of target - Find out more
Just picked up a 12000mAh li-ion battery pack for my iPad. I've just used it to top off the iPad battery and it's unpleasantly warm to the touch - probably nudging 40C.
I can understand it getting hot when charging, but should Li-Ion get warm while *discharging*?
The Li-Ion reaction is actually endothermic when charging, exothermic when discharging - they can be prone to thermal runaway effects, that's why they all have (or should have) a battery management system to keep them under control.
I'd keep an eye on it, any sign of the casing warping, put it outside in an open space.
If you discharge them quickly enough, yes. Flying RC models it's normal for the battery to be hot at the end of a flight. The internal resistance in the battery generates heat as current flows through it.
Yes.
Picking a high discharge rate lipo up after a 7 minute final in a modified 4wd rc class could leave you with a nasty surprise. I've measured 40+ degrees.
Touching the speed controller or battery is far worse though!
It's one of the reasons phones get hot while working hard. Yes the processors get hot, but the energy involved isn't actually that great.
Yes!