So my flight time is really short, 2-4 min on a battery(eflights). once my battery hits 7.76 volts I have no more lift. it takes about 2-3 min to hit that point. any ideas, it happens to all my eflight batteries. I have the same issue with my DN packs but they now act like eflite batteries. Any ideas, I also have tried to rebalance them by draining the cell that has more voltage to match the other battery.