Excessive battery drain using otg cable

[AC Question]

I used otg bluetooth mouse on galaxy tab s2 8in
Which led to instant battery drain and heating, I thought it was going to explode.
I am not using mouse again for sure.

But what could be the explanation?
And will it happen again when I turn tab on?

 

[Rukbat]

OTG turns the phone into a power source for what's connected to the cable. (Normally, power flows into the phone on the USB port.) If the mouse is drawing a lot of power, that would cause the phone to heat up. Bluetooth mice don't need cables, except to charge the internal battery. Plug the mouse into your computer overnight (or into the phone's charger). Then use it without any cable connected to it until it needs to be recharged.