Gens ace G-Tech 850mAh 4S1P 14.8V 60C Adventure RC car Lipo Battery offers you a very high power and very long run time for your RC cars. These batteries packs are made with superior Lithium Polymer raw materials from Japan and Korea. The advanced stacking technology enables a single cell of capacity to reach 850mah. They are widely fit the Upgrade RC 4WD Bully II Crawler. They are your ideal choice for the RC car hobby.