The Carrera Li-Io battery 7.4 V 900 mAh provides power for the RC model. The Carrera RC tuning accessories offers up to 20 percent longer driving pleasure. Just select the appropriate tuning battery charger and tuning for the radio-controlled RC vehicle or boat select and attention to the correct voltage (V) and milliampere-hour (mAh) eighth. Not for any RC car or boat tuning is possible.