VNR1554 - Venom 20C 2S 4000mAh 7.4V Hard Case LiPo Battery with Universal Plug System. $39.99 | RC Street Shop
7.4V 1300mAH Lipo Battery For Remote control helicopter Li po battery 7.4 V 18500 20C discharge toy batteryCylindrical|Replacement Batteries| - AliExpress