This is the Traxxas 2S, 7.4V, 2200mAh, 25C "Power Cell" Li-Poly Battery Pack with iD Traxxas Connector. This battery requires a Traxxas iD equipped LiPo charger to balance-charge!
Traxxas Certified iD-Equipped LiPo batteries are engineered to provide the punch and on-demand power for reaching the top speeds that Traxxas models are built to achieve. Available in a full range of capacities in 2-cell (2S) and 3-cell (3S) configurations, Traxxas Power Cell iD-Equipped LiPo batteries are engineered specifically to fit Traxxas models and maximize their full performance potential. Only Traxxas gives you more of what you want most: simple installation, a great price, and the most speed and run time available.
Accessory part for these models: