I've had this same issue happen with "off brand" tablets such as RCA etc. They are cheap and as such dont usually last long. Most of the tablets have very poor batteries, so most likely it's the battery that needs to be replaced. It's up to you whether you feel it's worth repairing. Most of the time the parts are as much as a used tablet. Im not sure if this is the case for your tablet or not as I didnt look up the cost of the battery. Other things to check are to try a different charge cable to make sure the battery is getting charged enough and also the charge ports can be a problem as well.