HP 646132-001 Battery for Real-Time Clock (RTC) - Includes cable and double-sided tape HP 430 431 436 630 631 635 636 2000, HP CQ43 CQ57 CQ58, HP Mini 420 & others HP 646132-001 Battery for Real-Time Clock (RTC) - Includes cable and double-sided tape HP uses two different manufacturers for the Backup Battery per HP P/N 646132-001 (Newsun & KTS) they are equal one to another and replacement can be either one. This is a internal motherboard cmos battery that would require replacement for the Notebook will start to lose the date and time keeping of the Notebook & boot process. This battery will not solve 601 battery errors that are caused by the Main Primary battery.