This is the A123 9.9V 2300 Li-Ion Nano Phosphate Hypersonic Battery Hump Pack A123�s packs offer superior power not only on land but also on the open water. When used with A123s Sonic Charger (AQR400088), you can charge up each pack in only 15 minutes. A123Racing batteries can be used in most RC vehicles whether it be car, truck, boat, or electric flight.