Visit Amazon sites : br DELL Latitude D800 CMOS RTC Reserve Battery W0124br br Genuine Dell Assembly DPN W0124vis a VARTA green 72 volt ni-mh rechargeable battery with 3 pin connector plug The plug fits on to the motherboard providing the voltage of the battery to the bios Over time these batteries stop holding charge and need to be replaced br Varta is the single source manufacturer on this assembly to Dell You will recognize a Varta brand battery by its Logo and brand name printed on the battery along with its traditional green color br Varta has specific quality standards with their product and engineered specifically for Dell br This is a rechargeable nickel metal hydrite cmos battery that the motherboard charges when drained br Refer to Dells Support on your specific model