Cmos bios battery (RTC Battery) are for HP Envy 15T, Pavilion 11-N Series that use the models 755735-001 (compatible, not oem rtc battery usage on repairs of the motherboards) The renewal or replacement process might be something that can be somewhat challenging depending on the specific model of notebook, yet in most cases technical manuals will allow the scope of it's replacement process and allow owners to replace and renew the cmos battery. If in doubt, please ask us to assist or redirect you to that source help. ________________________________________________________________________________________________________ HP equipment, notebooks that came into the public market from 2008 forward, that have the motherboard bios provisions of HP PC Hardware Diagnostics UEFI to test the main components of your notebook computer. This HP UEFI 2008 firmware has a internal diagnostic test that includes a battery health charge level, encompass the ability to alert the end user of the battery charge level associated with the internal battery (10.8v to 11.1v battery that subs for the ac/dc charger 100-240vac) If you have a 601 battery error, contact HP, or replace the internal battery not the rtc cmos battery. HP motherboards nearly never have a charging circuit for the rtc cmos battery. Any attempt to charge a rtc battery can leak and explode due to internal heat pressure, that the rtc battery will never be subjected to in it's internal proper use.