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@davet2001
Last active May 31, 2025 12:57
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Battery low warning home assistant blueprint
blueprint:
name: Low battery level detection & notification for all battery sensors
description: Regularly test all sensors with 'battery' device-class for crossing
a certain battery level threshold and if so execute an action.
domain: automation
input:
threshold:
name: Battery warning level threshold
description: Battery sensors below threshold are assumed to be low-battery.
default: 20
selector:
number:
min: 5.0
max: 100.0
unit_of_measurement: '%'
mode: slider
step: 5.0
time:
name: Time to test on
description: Test is run at configured time
default: '10:00:00'
selector:
time: {}
day:
name: Weekday to test on
description: 'Test is run at configured time either everyday (0) or on a given
weekday (1: Monday ... 7: Sunday)'
default: 6
selector:
number:
min: 0.0
max: 7.0
mode: slider
step: 1.0
notify_device:
name: Device to notify
description: Device needs to run the official Home Assistant app to receive notifications
selector:
device:
integration: mobile_app
variables:
day: !input 'day'
threshold: !input 'threshold'
counttotal: >-
{% set data = namespace(battery_list=[]) %}
{% for batt in states.sensor | selectattr('attributes.device_class','eq','battery') -%}
{% set data.battery_list = data.battery_list + [{'name': batt.attributes.friendly_name, 'level_int': batt.state|int(0), 'level_str': batt.state}] %}
{%- endfor %}
{{ data.battery_list | count }}
countlow: >-
{% set data = namespace(battery_list=[]) %}
{% for batt in states.sensor | selectattr('attributes.device_class','eq','battery') -%}
{% set data.battery_list = data.battery_list + [{'name': batt.attributes.friendly_name, 'level_int': batt.state|int(0), 'level_str': batt.state}] %}
{%- endfor %}
{{ data.battery_list
| selectattr('level_int', 'lessthan', threshold)
| list
| count }}
listtextlow: >-
{% set data = namespace(battery_list=[]) %}
{% for batt in states.sensor | selectattr('attributes.device_class','eq','battery') -%}
{% set data.battery_list = data.battery_list + [{'name': batt.attributes.friendly_name, 'level_int': batt.state|int(0), 'level_str': batt.state}] %}
{%- endfor %}
{% for batt in data.battery_list
| sort(attribute='level_int')
| selectattr('level_int', 'lessthan', threshold)
%}
{{ batt.name }} is {% if batt.level_int != 0 -%}
{{ batt.level_int }}%
{%- else -%}
{{ batt.level_str }}
{%- endif -%}
{%- endfor %}
notification_message: "{% if countlow > 0 -%}{{countlow}} out of \
{{ counttotal }} device batteries are low:
{{listtextlow}}
{%- else -%}
All {{counttotal}} device batteries are ok!
{% endif %}"
trigger:
- platform: time
at: !input 'time'
condition:
- condition: template
value_template: '{{ sensors != '''' and (day | int == 0 or day | int == now().isoweekday())
}}'
action:
- device_id: !input 'notify_device'
domain: mobile_app
type: notify
title: 'Battery Check'
message: '{{ notification_message }}'
- service: persistent_notification.create
data:
title: 'Battery Check'
message: '{{ notification_message }}'
notification_id: battery-check
@Erickclee
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Hi @davet2001, thanks for this modified blueprint. It helps. There is some small bugs when we select threshold at level5% and 100%. when select 5%, system see it as 50% and report battery that is <50%, when select 100%, system report all battery OK. Could you help to see if this can be fixed? Thanks for your help.

@EQNish
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EQNish commented Jan 25, 2025

not sure if this is still active, but when I'm running the blue print, I get all my sensors reporting, not mater what threshold I select, and no mater what the batteries levels are
select 20% threshold, lists every dive, some with 23% battery, some with 99% battery

@ScaredyCat
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For anyone else just finding this, I don't think it works any more. Devices all report as being fine even if they fall below the threshold you set.

@davet2001
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davet2001 commented May 31, 2025

Hi All, been a long time since I touched this. Yes, I found a problem recently as well. I think the entity_id attribute got removed from one of the structures I was using.
Also @Erickclee there were some shortcuts being taken here for sure - e.g. the list was being sorted by string version of battery percentage, meaning silly sort orders like 0, 1, 100, 12, 3, 50, 9. I've fixed that now.

Also, important: I've made it handle unavailable sensors now, which was a niggle all along. Previously, once a battery got so low it went offline, it disappeared from the list. Now it shows at the top of the list.

The end result for me and I expect many others, is that this blueprint will now show you a whole load of long since forgotten devices, and probably some devices reporting batteries that don't even have them. That prompted me to remove lots of old devices from my setup and 'un enable' bogus battery sensors in the config. Please re-import and comment back here if you have any further issues.

Thanks!

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