Battery Technology (BTI) is a global supplier of replacement batteries and AC power adapters for notebook computers, batteries for digital cameras, PDA's, and other mobile devices and batteries for APC UPS systems. Features 100% OEM compatible and 30-40% less expensive than the OEM. Replacement battery for HP Compaq laptop. Features 4210mAh capacity and four cells. Li-ion chemistry allows for long-lasting quality without memory effect. Battery energy: 64Wh. 15. 2V output voltage. 18-month manufacturer limited warranty