Orin nano with L4T35.4.1 RTC is not saving

Dear nvidia team:
Orin nano with L4T35.4.1 RTC is not saving.I follow the steps below to test:
1.Use the command “hwclock -w” to write system time to RTC.
2.check the status:
ls /dev/rtc* -la
/dev/rtc → rtc0
3.Cut off the power to reboot.
4.After reboot,I used the command “hwclock -r” to check the time and found the time of the year is still 1970.


Do you have a dedicated battery connected to the carrier board?
Without a battery, the RTC can only save time with a warm reboot, but not a cold reboot.

Yes.the battery is connected to the carrier board.

Have you checked the voltage of the hardware pin after power off?
Jetson_Orin_Nano_DevKit_Carrier_Board_Specification_SP-11324-001_v1.1.pdf (nvidia.com)

Sorry. I can’t get the download link.

Oh, sorry.

I just meant this page:

The carrier board + Jetson Orin NANO(L4T35.4.1) PIN 235(PMIC_BBAT) Voltage is 3.0V, and the carrier board + Jetson Orin NX(L4T35.3.1) , RTC time can be saved, Any difference between the two kinds modules?

You mean with the same carrier board and battery, RTC works with Orin NX but not Orin Nano?
Is it a DevKit?

Yes.But not the same L4T packet branch.

Please verify with the same L4T version.
Maybe also try the latest 36.2.

I have already tried that the (carrier board + Jetson Orin NX 16G) test OK by using the same L4T version(35.4.1).

35.4.1 + Orin NX = OK?
35.4.1 + Orin Nano = NG?

How about this?

35.4.1 + Orin NX = OK
35.4.1 + Orin Nano = NO

I have no devkit.I test it on our own customer carrier board.

Then please find a DevKit for validation.
We can only help if it’s replicable on DevKits.

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