Why won't my tablet turn on or even charge?

Hello

I have a samsung tab 3 10.1.

It is not running the original battery or the port. I changed them years ago.

Lately it started turning off and refusing to trun on or charge no matter what keys i press or what charger i use.

After i leave it for a month or so it turns on with the battery at 0%. It charges normally and turns on without any problems before repeating everything again.

What can i do to stop it from turning off.