Tentacle won’t turn on

Hi,
I have a tentacle (cabled version) i bought in 2015. I didn’t use it much all this years, but every time i used it and needed it was working fine. I’ve rented it for a shoot for 4 days last week. When i got it back, i tested it and it was ok. Today i’ve rented it for another shoot, and yesterday night i plugged it into my iPhone to set fps and other things. I also charged it, everything was pretty ok.

Today i got a call from the sound mixer that was in set saying tentacle wouldn’t turn on. He tried charging it but charging light wouldn’t turn on also. I just received back and its really not even turning the light on when i try charge it.

Question is: is it possible that problem is a dead battery? Or it should be another problem? Do i have access to a new battery, or possibly to a technician i can send a diagnose the problem? As i live in Brazil its a little bit complicated to send Europe or US, but its possible.