Low battery alerts

Subject of the issue

I am getting the following in the log

vent.system.kernel.timestamp: '2020-07-08T14:43:38,201096+0100'

event.system.kernel.message: 'rtc-pcf8523 1-0068: low battery voltage detected, time may be unreliable'

event.system.kernel.level: err

event.system.kernel.facility: kern

Your environment

  • software 2020.05.27

Steps to reproduce

None. The dongle is connected to static 12V power on the lab bench using the correct adapter.

Expected behaviour

Tell us what you expect should happen

Actual behaviour

Tell us what happens instead

Output of power.status command

If your issue is in any way related to the device shutting down or behaving in a unexpected way, please provide the output of the power.status command to help us diagnose the issue.

Run the command


in the terminal on local.autopi.io, and paste the result here.

    users: 3
    seconds: 20846
    since_t: 1594195570
    days: 0
    since_iso: '2020-07-08T08:06:10.502052'
    time: '5:47'
    state: charging
    voltage: 14.2
    level: 100
    sleep: NONE
    wake: NONE
    vl_wake: '  >13.20V FOR 3 s'
    vchg_wake: '  +0.40V IN 1000 ms'
    uart_sleep: '  900 s'
    vl_sleep: '  <12.20V FOR 240 s'
    ext_sleep: '  LOW FOR 3000 ms'
    ext_wake: '  HIGH FOR 500 ms'
    down: none
    up: 'on'
  sleep_interval: 0
  version: '2.0'
  current_state: 'on'
    down: none
    up: spm

Do’s & dont’s

  • Do not write your unit-id anywhere.

Hi Gareth.

It seems like this is an issue with the real time clock (rtc). This error usually occurs when the battery connected to the real time clock is either disconnected or out of charge. If you have a DIY edition of the AutoPi, please make sure that you have a battery connected to the real time clock.


Thanks, Nikola. That makes sense.
I’ve searched, but I can’t find anything regarding spec, pinout etc for the RTC battery: indeed anything for the Gen 3 product. Can you point me in the right direction?

Hi Gareth.

You can take a look at where we plug the RTC batteries on the devices we build:

And here’s a close-up image:

Please note that the battery must be 3.3V.

Is this the information you’re looking for?


Thanks, Nikola.
Unfortunately that doesn’t help as regards polarity or voltage. I can’t see any markings on the board.


What is the connector type used for the RTC?

I had found this one and I believe it correct but I wanted to confirm:


Apologies for the delayed response.

We’ve double checked and unfortunately, the product you’ve linked won’t work because the pins are too far apart (1mm). This one will, however.


Ok. Awesome, thanks for the help. I will order that one.

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