... LED battery indicator and a battery test switch, real-time check the battery pack power, use more convenient.Big 4pin with 1pc ... ; 5. Output current: ≤1A Battery indicator: Press the battery test switch, power on, LED light indicates that there is 5V output voltage ... output. Then press the test switch ≥ 3 seconds, the power is off. Turn on the power, if no external load, 3 minutes ...