Back at the end of 2022 I wrote about Aqara’s P1 Motion Sensor – but then I looked a couple of weeks ago at their press releases and saw the word NEW in there – something to do with improved battery life I wonder? Anyway one of them just turned up so here it is – no change of battery… the unit comes complete with a CR2450 just as before – but now they’re making a big deal about “up to 5 years battery life”… got to be worthwhile if changed… Anyway as it is sitting in front of me just begging to be connected, I though I’d put “pen to paper” here.When I last wrote about the P1 was as I said above, 2022.The unit features movement AND light level sensing and supposedly the “Aqara Zigbee 3.0 Hub is required” to operate – except that it ISN’T – as I connect my Zigbee devices to Zigbee2MQTT – originally on the Raspberry Pi with a Sonoff Zigbee coordinator and then through Node-Red – but these days that’s all changed.
I run Home Assistant – and Zigbee2MQTT on a Zima board.I use an Ethernet-based coordinator – much better idea as it can be ideally centrally placed using an Ethernet lead as against stuck next to an RPi or whatever.So, fresh start and another chance to use the P1 sensor, this time hopefully with that 5 year battery life – I’ve recently started to move back to USB-powered ESP-based temperature sensors as I’m sick of changing batteries all the time (see the Apollo TEMP-1 article) but I’ll give this a shot due to their battery life claim.
Let’s have a look.Out of the box… these days I keep a supply of CR2032 and CR2450 batteries lying around – cheap and widely used.As it happens the battery is already pre-fitted.
I wwent off to my Zigbee2MQTT sidelink in Home Assistant and told it to look for nwe devices – nothing.And no flashing light on the P1 either.SO, I held in the TEST/RESET button on the side and tried again.
Sure enough – flashing bright blue light… and went back to Zigbee2MQTT once again enabling new devices to join.Straight in – “successfully interviewed”.Next impo0rtant task – give it a useful name – as I alreay have the original P1.
“Aqara P1 2025” seems reasonable.With the device accepted I hit the rename and inform Home Assistant box in Zigbee2MQTT… Job done… just need to have a look in Home Assistant settings – entities” to see what’s available… It doesn’t get any easier – a load of new entities appeared immediately – and so I added a couple to my SENSORS page just to play with.Unfortunately I can’t really test the 5-year claim as it’ll take – well, 5 years.
Meanwhile – lots of new entities to play with – and no effort – it took me a LOT longer to write this than to get the P1 going.the unit sticks onto the base with the supplied sticky pad (spare included) and the base itself can stick onto a wall.AND it looks like this is my THIRD.
The previous version is running just fine – the FIRST did nothing when pressing the button – thankfully even with the sticky pad in place, the bottom comes off easily to replace the battery.As it happens – I took off the bottom – just a misplaced battery.Replaced the base – nope – there are in fact TWO CR2450 batteries in there – 3.3v when new, one was 3v, the other 2.7v.
I replaced them both.And after screwing the operation up twice – the original is now working – counter-intuitively the two batteries run run parallel and the + sides are on the outside in each case.Of course I got it wrong and momentarily shorted the batteries – dropping the voltage to 2.7v at which point the unit would not work.
After a moment the batteries recovered back up to 3v – one working P1 sensor….but for sure the original did not work for 5 years – we’ll have to wait and see – maybe this time turn off the blue light on movement… Thinking about it the instructions refer to “battery” – not “batteries” – they could make this and the fitting directions a lot clearer.But the P1 itself – just fine.