Wired Nest Protect: Battery backup replaced - but Nest still warning that batteries need replacement

[MarkPowderly]

One of my x5 wired Nest Protect Gen2s (2017) has developed what seems to be a fault. It has flagged that the three Energizer Ultimate Lithium (L91) batteries inside need replacing, and is firing audible warnings when plugged in.  I have removed the batteries, purchased exactly the correct type (*which on the box states the new batteries have an expiry date of Dec 2050*) and yet I still get the audible warning and error message in the app stating the batteries need replacing. I have tried multiple soft and hard resets and now purchased a second set of new batteries, but I still have the fault. The battery contacts have been cleaned and are in good condition. And today I tried a full reset and re-installed the Nest Protect as a new product. I still have the issue. Is there anyone who can help point me to some support to get this fixed? Many thanks for any suggestions/help!! 

[Derickf]

Hi @MarkPowderly,

Thank you for posting in the community. I'm sorry to hear that your Nest Protect (2nd gen) is giving you a persistent low battery alert. I appreciate you confirming that you've already gone through some troubleshooting steps. I'm happy to assist.

To gather the necessary information, please answer the following questions:

• Have you tried doing the safety checkup? If not, please follow the steps below:
  1. On your Nest Protect:
  2. Press the Nest button on your Nest Protect. The blue light should turn on, and it will speak to you.
  3. When it says "Press to test," press the button a second time.
• Could you confirm if the 2017 date is the date the device was made or the date you bought it?

I'll be waiting for your reply.

Best regards.

Derick.

[MarkPowderly]

Hi Derickf, so sorry for the delay replying, I haven't checked in for a while. The unit was manufactured June 2017 and we purchased it in November 2017. I carried out the steps as you instructed: the test was successful for a) smoke b) carbon monoxide and then the other four units in our house also completed tests - the unit then reported back and said "the test is finished, everything looks fine"