Noiposi 4 pcs 3.7v 850mAh 25c Upgrade Lipo Battery (JST Plug) with X6 Charger for MJX X400 X400W X800 X300C Sky Viper S670 V950hd V950str HS200W National Geographic Quadcopter Drone Tips:,the battery is thicker than the original battery for sky viper v2400.When it is put into battery compartment ,it is very tight .If you are willing to modify it ,you could buy for sky viper v2400 Multifunctional Chagrer :the charger is with Over charge protection, Short circuit protection.while the voltage of battery is close to 4.2v ,the charger will stop .it will protect batteries from the damage .Thus ,the lifetime of batteries will be longer Connector type :JST Compatible With :MJX X400 X400W X800 X300C Sky Viper S670 V950hd V950str HS200W National Geographic Quadcopter Drone Well-designed appearance and new package :if you want to buy a gift for your relative ,friend or yourself ,it is a good choice