No problems. Never counted just use a little voltmetter before flying to check percent of charge. I have raced all weekend (9 or10) heats without needing to recharge. http://www.hobbycity.com/hobbycity/s...idProduct=6589 This is what I check the battery with. If the lowest cell is below 3.80 volts I recharge. Plus it only takes an hour for a full charge