To reset the battery and test if it needs replacement, leave it to fully discharge in the tablet with the charger unplugged, so the tablet turns itself off, then plug the charger in the switched-off tablet and wait for the battery light to turn green. It will take a quite long time, but if the light does not turn green after an overnight charging, the battery needs replacement.
Another sign of a bad battery is if the green light comes up shortly after plugging in the charger, but the battery discharges after a very short time. In this case try the reset procedure and see if it improves the
If you need a replacement battery for your tablet, you can purchase one directly from TabletKiosk. Go to the website, www.tabletkiosk.com and click “Products” then “Accessories”. Select “Batteries & Power” then find the battery that matches your tablet. All tablets are Sahara Slate. Look at the sticker on the back of your tablet to identify what series number your tablet is.