My Q500 4K, is less than 30 days old. It has flown only 3 times, in part, waiting for a replacement camera from Yuneec. Each flight I landed at first warning, and didn't recharge until right before the next flight. At second charge, the charger became real hot charging only one of the batteries. The other battery did not result in the hot charger. On Saturday, (day 23) after the 3rd charge, the one charger hot battery, upon take off, the low voltage warning came on. I landed quickly with no issue. Today, called Yuneec, Mike said appears the one battery is bad... Batteries only have a 1 month warranty.... If, I am inside one month of purchase, they will replace it. I am, so no concern. I pointed out the written warranty is 6 months, and mentions nothing about battery limited to one month. Mike disagreed. The written warranty, "...accessories are guaranteed against manufacturing defects for six (6) months from the original date of purchase."