How long has the tablet been on charge and was the tablet on or off during this period? I reckon mine takes about 1.5 hrs to go from 60% to full when the tablet is fully off but can take more than double that time if the tablet is being used. If the tablet is rarely used the battery will spend most of its time self discharging which is not ideal even for a li-on cell. I normally would advise using the unit until the battery discharges to almost zero then recharge but due to some of the problems associated with this procedure I wont advise it. Try using the tablet more to see if this improves the situation.
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