It just works. Not more then that. Capacity is not correct.

This unit works. To test i have removed the + cable from the battery of a 1.6L petrol car. I was able to make a cold start 4 times easy on this unit. So to start a car works. The capacity if 16800 is not correct. I have opened up the unit, inside there is a battery That is about 12x3x3cm big. Underneath the plastic foil i could read "4000 mAh" These Are 3 batteries layers stick together. So 3x 4000 is 12,000 mAh. The voltage of each battery is 3.7 volts. so 3.7 x 12amps is a maximum capacity of 44 watts hour. This is not Achieved. I have attached a 12-volt light bulb. Using 0.77a. So THAT is 9.2 watts hour. It lasted only for 2 hours and 15 minutes. So the actual capacity for 12 volts is about 21 watts hour.