This Li-Ion Hydride battery from Battery Technology, Inc. can be used as a replacement for the original battery if it has been damaged or misplaced, or as a second battery to keep charged for extended notebook usage when AC power is not available. The battery meets or exceeds the original equipment manufacturer's specifications. Don't let yourself be caught without power for your notebook when you need it. Get charged up with BTI's high-quality notebook battery products! This battery is designed for IBM ThinkPad 600 Series.