Original ODSTAR X300 DP (Key Master DP) key programmer comes with 2 power supplies. Recently some customers mixed use these two which cause the low battery issue.
OBDSTAR Key Master DP Power Supply Warning:
Please charge for the pad according to instruction manual when the battery is low.
Please charge with 5V power provided by our company or the other companies.
Never use power more than 5V to charge to avoid any damages of the machine.
Power supply marked #2 (5V) above: used to power up OBDSTAR X300 DP pad/tablet. http://www.key-programmer.org/2017/04/11/obdstar-x300-dp-power-supply-warning/