Problems charging Android tablets usually stem from either the charger or the charging port itself. If you notice your tablet isn't charging, set it to Air plane Mode and reduce the brightness to extend the battery life while you work to solve the problem. Back up your files while you can, in case the problem can't be solved at home.
Sometimes the problem is with the charging port of the tablet itself. Examine it to see whether it's bent or misshapen. The connector on the charging cable needs to be able to fit well, so that all the pins on the charger are correctly attached to those on the port. If your port is damaged, it may need to be fixed or the entire unit may need to be replaced. You should also check the connector on the charging cable to make sure that port is correctly shaped and not damaged.
Sometimes using an incorrect power adaptor can prevent a tablet from charging. Look at both the base of the adaptor that plugs into an outlet and the cable itself. Very long extension micro USB cables, for example, charge more slowly than shorter OEM cables. Check the manual that came with your tablet to see what type of charger you need. If you're charging the tablet from a computer USB port, it may prevent the tablet from charging correctly. Use a wall adaptor and see if it fixes the problem.
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