RTC battery on board？

plumlis

I saw there is an RTC battery slot on mainboard.
Is it possible to add a RTC battery on it?

cool pi laptop with ubuntu 24.04 seems won't save datetime after powered off.

checked /proc/driver/rtc it works fine but won't sync to system datetime.

george

@plumlis
Firstly, there is no need to add a separate RTC battery on the motherboard. RTC defaults to using the system's 38WH battery storage time.
The issue of not being able to save time is a system software issue, not an RTC hardware issue. This can be confirmed by the following command:

cat  /proc/driver/rtc

Regarding how to synchronize the hardware RTC time to the system, the following command can be used:

timedatectl set-local-rtc 1 --adjust-system-clock

We will try to modify and add it to the system later. Thank you for your support.

plumlis

@george
I already tested.

cat  /proc/driver/rtc

works quite well, but its UTC time.

after

timedatectl set-local-rtc 1 --adjust-system-clock

System dateime will sync to UTC with out +8 beijing region.

plumlis

Could you tell me what's the type of RTC battery connect pin?

1mm? 0.8mm?

I'd like to have a try.

george

@plumlis
The battery of the RTC connector has a spacing of 0.8mm. From the current phenomenon, it is not that the hardware RTC cannot save time, but rather that the hardware RTC time has not been synchronized with the system. So adding this battery won't make any changes.