battery_last_replaced attribute of new Battery Notes services defaulted to Home Assistant start time

[rparenton]

Checklist

• I have restarted Home Assistant after the HACS or manual install.
• I have read the FAQ's.
• I have enabled debug logging for my installation.
• I have filled out the issue template to the best of my ability.
• This issue only contains 1 issue (if you have multiple issues, open one issue for each issue).
• This issue is not a duplicate issue of any previous issues..

Battery Notes Version

3.4.6

Describe the issue

When creating new Battery Notes services for devices, the battery_last_replaced attributed on the various entities is set to the Home Assistant start time.

This may be related to the fix for #4714 (PR #4715).

Reproduction steps

1. Add a Battery Notes service for a newly discovered device
2. Check the battery_last_replaced attribute in Developer Tools

System Health details

System Information

version	core-2026.5.4
installation_type	Home Assistant Container
dev	false
hassio	false
docker	true
container_arch	amd64
user	root
virtualenv	false
python_version	3.14.2
os_name	Linux
os_version	4.18.0-553.121.1.el8_10.x86_64
arch	x86_64
timezone	America/Chicago
config_dir	/config

Home Assistant Community Store

GitHub API	ok
GitHub Content	ok
GitHub Web	ok
HACS Data	ok
GitHub API Calls Remaining	5000
Installed Version	2.0.5
Stage	running
Available Repositories	3130
Downloaded Repositories	17

Home Assistant Cloud

logged_in	false
can_reach_cert_server	ok
can_reach_cloud_auth	ok
can_reach_cloud	ok

Dashboards

dashboards	6
resources	12
views	26
mode	storage

Network Configuration

adapters	lo (disabled), ens3 (enabled, default, auto)
ipv4_addresses	lo (127.0.0.1/8), ens3 (10.2.97.3/24)
ipv6_addresses	lo (::1/128), ens3 (fe80::7c67:fe0b:a347:b288/64)
announce_addresses	10.2.97.3, fe80::7c67:fe0b:a347:b288

Recorder

oldest_recorder_run	May 9, 2026 at 10:54 PM
current_recorder_run	May 23, 2026 at 2:16 PM
estimated_db_size	2549.94 MiB
database_engine	mysql
database_version	10.3.39

Debug logs

2026-05-28 10:23:58.270 DEBUG (MainThread) [custom_components.battery_notes.coordinator] sensor.m100111908_battery low threshold set at 10
2026-05-28 10:23:58.270 DEBUG (MainThread) [custom_components.battery_notes.coordinator] Defaulting 9b851bdd1c91681f80aa827debd5dee3 battery last replaced to 2026-05-23 19:18:51.237041+00:00
2026-05-28 10:23:58.270 DEBUG (MainThread) [custom_components.battery_notes.coordinator] Defaulting 9b851bdd1c91681f80aa827debd5dee3 battery last reported to 2026-05-28 15:23:58.270589+00:00

Diagnostics dump

No response

[andrew-codechimp]

Hi, when adding a new battery note it will try to determine the last_replaced as the date the device was added to Home Assistant, as recorded in the device registry. That's dependant on the integration adding the device (MQTT for example will put in the date it's first discovered in HA) so what you're seeing here is probably correct as it's the best guess on how long the battery has been in there already until you replace it. If you know a different date you can use the set_battery_replaced action with a specific date to get it accurate but adding a date by default at least gives you some indication until you replace it after having added the battery note.

The button entity is when the button was pressed so that's correct to be unknown.

The issue/fix you point to is just a fix for the button press not updating the attribute so not related.

[rparenton]

Is that new(ish) functionality? The attribute on all of my older Battery Notes services is null. The problem this best guess causes is that the "Battery last replaced" timestamp in the device Diagnostic panel on newly added devices shows a value that's incorrect because the battery has never been replaced. The set_battery_replaced action doesn't appear to allow me to set null.

[andrew-codechimp]

It's been there for quite a while, but HA only added device created fairly recently (last 6 months at a guess), so if your other devices were added to HA before that then they will default to Null/Unknown as their date will be 1970 within the device registry.

Unfortunately no, you can't set a replaced to unknown.

[rparenton]

Thanks for the info. I'll manage to adapt to the new (to me) behavior.