Estes Battery - Proto X FPV LiPo 1S 3.7V 650mAh This is the 1S 3.7V 650mAh LiPo Battery for the Estes Proto-X FPV Ready to Fly Micro Quadcopter, ESTE4716.Features: Stock replacement battery for the Proto-X FPVCharges from computer with USB charge cord, ESTE4565Includes: 1S 3.7V 650mAh LiPo Battery with White 2-Pin Connector