# Raspberry Pi 5 Real-Time Clock (RTC) Battery (CE09774)

**URL:** https://forum.core-electronics.com.au/t/raspberry-pi-5-real-time-clock-rtc-battery-ce09774/22456
**Category:** Product Questions
**Created:** [13 May 2025 05:09 UTC](https://forum.core-electronics.com.au/t/raspberry-pi-5-real-time-clock-rtc-battery-ce09774/22456 "2025-05-13T05:09:20Z")
**Posts on this page:** 4
**Page:** 1

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### Author: ![Core](https://yyz2.discourse-cdn.com/flex028/user_avatar/forum.core-electronics.com.au/core/32/57_2.png) [@Core](https://forum.core-electronics.com.au/u/Core)
#### Post date: [13 May 2025 05:09 UTC](https://forum.core-electronics.com.au/t/raspberry-pi-5-real-time-clock-rtc-battery-ce09774/22456/1 "2025-05-13T05:09:20Z")

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This is a placeholder topic for [**“Raspberry Pi 5 Real-Time Clock (RTC) Battery”**](https://core-electronics.com.au/raspberry-pi-5-rtc-battery.html) comments.

![](https://core-electronics.com.au/media/catalog/product/cache/5ba536955e3e815f4e908e49c1dd8155/r/a/raspberry-pi-5-rtc-battery.jpg)

Keep your Raspberry Pi 5 on time even when the power is disconnected with the Real-Time Clock (RTC) Battery.

[**Read more**](https://core-electronics.com.au/raspberry-pi-5-rtc-battery.html)

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### Author: ![Greig63365](https://yyz2.discourse-cdn.com/flex028/user_avatar/forum.core-electronics.com.au/greig63365/32/11384_2.png) [@Greig63365](https://forum.core-electronics.com.au/u/Greig63365)
#### Post date: [13 May 2025 05:09 UTC](https://forum.core-electronics.com.au/t/raspberry-pi-5-real-time-clock-rtc-battery-ce09774/22456/2 "2025-05-13T05:09:41Z")

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This is a nice little battery, but I think the text in the description field is flawed.

That shows how to enable a low-current wake on alarm, which is of zero use to me.

What it omits is how to enable charging and how to test the battery’s voltage.

"To charge the battery at a set voltage, add rtc\_bbat\_vchg to /boot/firmware/config.txt:

dtparam=rtc\_bbat\_vchg=3000000

Reboot with sudo reboot to use the new voltage setting."

Reference: [https://www.raspberrypi.com/documentation/computers/raspberry-pi.html](https://www.raspberrypi.com/documentation/computers/raspberry-pi.html) (Search RTC and you’ll get there eventually)

“vcgencmd pmic\_read\_adc BATT\_V” will report the voltage.

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### Author: ![Zach](https://yyz2.discourse-cdn.com/flex028/user_avatar/forum.core-electronics.com.au/zach/32/10899_2.png) [@Zach](https://forum.core-electronics.com.au/u/Zach)
#### Post date: [13 May 2025 06:02 UTC](https://forum.core-electronics.com.au/t/raspberry-pi-5-real-time-clock-rtc-battery-ce09774/22456/3 "2025-05-13T06:02:10Z")

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Hey @Greig63365,

Good spot! I’ll get the description modified to better align with Raspberry Pi’s official documentation.

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### Author: ![Greig63365](https://yyz2.discourse-cdn.com/flex028/user_avatar/forum.core-electronics.com.au/greig63365/32/11384_2.png) [@Greig63365](https://forum.core-electronics.com.au/u/Greig63365)
#### Post date: [13 May 2025 07:05 UTC](https://forum.core-electronics.com.au/t/raspberry-pi-5-real-time-clock-rtc-battery-ce09774/22456/4 "2025-05-13T07:05:39Z")

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Thanks Zach! I thought I was adding a note to the product, but if you can fix it in the listing that’s even better.

- Greig.