... . OVER, EMPTY.Alarm functionsOVER, OCCL., Air, Empty, Low battery, control abnormal, no AC power supply, installation error, serious ... polymer battery, 7.4V, 1600mAhBattery rechargeWhen the pump is connected to the AC power supply, turn on the power and the battery will ... automatically recharge (about 8 ~14 hours to recharge fully.)Electrical safety Comply with the ...