HP RTC battery 651948-001 is a replacement part for maintaining the real-time clock in compatible ProBook notebooks. HP’s service guide lists it for the ProBook 640 G1, 645 G1, 650 G1 and 655 G1 family.
The assembly includes a cable and double-sided adhesive. In the service procedure, the cable connects to the system board and the battery attaches to the base enclosure, making it a dedicated internal service component.
Use this part when replacing the RTC battery in a supported notebook model.