RTC Battery on HP Pavillion X360 14-dy

[mrnike75]

Hi everyone, 

would this computer be the first one in the world without RCT battery 😉?

I've been looking for this battery (removed the regular battery, looked in the maintenance guide) but did not find a trace of an RTC battery.

So your help would be greatly appreciated to help me locate this part.

Cheers

[Paul_Tikkanen · Accepted solution]

Hi:

There are now hundreds if not thousands of different notebooks that no longer come with RTC/CMOS batteries.

This trend started when PC manufacturers switched from external to internal batteries a couple - three years ago.

The main battery maintains the BIOS and clock settings.

Below is the link to the service manual for your notebook's model series.

Maintenance and Service Guide (hp.com)

Chapter 3 has the parts list.

You will find no RTC/CMOS battery part number or description.

Chapter 5 has the removal and replacement procedure.

You will find no procedure to remove or replace a RTC/CMOS battery.

[mrnike75]

Hi Paul, 

thanks for your reply and explanation.

I learnt something today ;).

The problem seems solved as it was probabely a corrupted bios error, for which i apply the recovery procedure.

So when the main battery is replaced on an rtc battery-free computer, does the bios/UEFI has to be set up again ? 

And how about the windows keys and device ID stored there ?

[Paul_Tikkanen]

You're very welcome.

Those settings are maintained by the main internal battery.

If the battery were to completely discharge or you disconnected it, you would get a CMOS 502 error.

I don't know what part of the battery actually controls those settings (if there is a specific cell in the battery that does that), but that is how those settings are maintained.