How long should/do batteries last? Today I removed the charged battery from my wall charger and screwed in the ded one and put my cart on it and puffed on it for about 10 15 minutes and the battery started flashing. It had been on the charger for about 6hrs and the light was green signifying a full charge. Now I am sitting here with nothing to vape and faceing the possibility of haveing to go smoke an analog. Which I have not had for 2 days! What went wrong???