Features: 3.7V 500mAh lipo battery; enough capacity and safe to use. 4 in 1 battery charger saves a lot of charging time. Over charge for protection for every charging port. Charging indicator tells the charging status of every pieces. A good replacement for you to enjoy more flying experience. Compatible with Wltoys F949 Aircraft Syma X5C X5SW X5SC X5HW X5HC RC quadcopter.