I got a couple of 510 batteries and the vapormaxx pcc. I have it plugged into the computer to charge the pcc, and it shows full charge. I put in a battery, close the lid, hold the button down, it turns green, continue holding, it flashes green 20 times, then turns red for 5 seconds. Should the light stay red till it's charged or is it supposed to go out after 5 secs?