Hi everyone I have just purchased a u9gt but I need to ask a question regarding the battery life. I understand that it is supposed to be on a 4000mAh battery. However, on the back of the u9gt(the silvery back), it says DC IN 5v == 2000mA. Does this mean my u9gt is only a 2000mAh and not the right 4000mAh? Have I been cheated? Please advice, thanks.