Sudden battery drain then tablet goes into constant bootloop.

[Android Central Question]

I have six NID-1002 tablets linked/synced.,four of them are only 1-3 months old . Every day at least one of the four has sudden battery drain to 0% then shuts down and starts constant boot loop cycle . I've tried numerous electric wall outlets //adaptors/USB cords that are for these model tablets. As soon as I get one back to working properly after a day or two of trying to fix it , about an hour later or so one of the others will develop the same issue. Today it happened to two of them almost back to back. This is getting very frustrating and annoying. Plus my SanDisk 32GB micro SD cards keep un-mounted at random. One of these tablets doesn't even have a SD card and still get "unmounted error" message. Can someone please offer a sure fix for these issues? Thank you in advance for a permanent solution.

 

[B. Diddy]

Welcome to Android Central! Considering they're all the same model, it could be a firmware bug. Or, if you installed the same apps on all of them, one of those apps might be "going rogue" and eating up battery. Does it happen in Safe Mode? On most Android devices, while powered on, press and hold Power until the Power Off menu appears. Press and hold the Power Off selection until the Safe Mode prompt appears. Tap OK.