Waterproofing Xiaomi sensors

Anyone have any good tips on doing this? Don’t really want to end up with a really bulky end result so am minded to just wrap in a clear plastic money bag? Or failing that just swathe in electrical tape? I’ve seen reports of people who have just stuck them outside unprotected and they’ve been fine.
My only concern is that I might lock in condensation !

What kind of sensor? If it measures temperature and humidity, making it 100% waterproof will prevent the humidity sensor from sampling the ambient air.

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I have one temperature sensor outside home. It’s on a corner of the window which (hopefully) doesnt get rain. So far so good…


It’s the door/window sensor. Wanting to stick it on a gate (pretty exposed) and not have it pack up within a fortnight’s time! :slight_smile:

The small part is only a magnet - I doubt the rain/sun/heat would harm it within a couple of years. Though, the colour of the plastic will probably change

The larger part you can simply put into a tupper box (or something similar), shrink wrap it, or build a tiny case out of acrylic glass. those are the solutions that pop into my mind for now :thinking:

It kind of depends on the area you want to put it. In the end, just make sure the rain can’t hit it - I think they are rated -20°C to 50°C and up to 95% humidity - so they should handle everything except for actually getting wet.

EDIT: also, expect the battery to perform a lot worse if it’s cold outside - this might even affect the range.

I have exactly this set up and have no protection on the sensor at all. The first one failed after about a year or so but may have been non-weather related and the second has been going strong with no issues for about 6 months. YMMV :slight_smile:

I also have a aqara door sensor outdoor (with no protection, no issues so far, it’s out there since some months)

You could dip them in plastidip. But when you have to change the battery you will have to pull off the coating and do it again.

I’m minded just to pop the sensor into a clear mini plastic bag with the seam end upside down and given that @greybags and @h4nc seem to be doing well even without this, surely things sound promising! Thank you!

Heya, sorry to revive an old thread, thought it might help someone though. I’ve had success with embedding the sensor in the actual gate frame (and magnet in the gate) with a bit of judicious chiselling.

When it’s closed its virtually waterproof anyway and it only stays open for a few seconds, for added protection the sensor is in a Ziploc bag :slight_smile:

Zero problems in 18 months (and also very inconspicuous).


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Hi can you share some photos and a little more explanation because I am interesting but cannot understand what you did?

Here you go, this is from the one I did most recently, though please note with this gate that “judicious chiselling” became frenzied drilling (my chisel was basically blunt),so it’s a really messy job. But hey, it’s a really old gate that we’re going to replace; and it works! Also on this one I didn’t put them in a plastic bag (as a bit of an experiment, I love these cheap sensors!)

  1. The first image is the actual sensor (the battery bit) in the gate post, I used a 12mm drill bit and just pushed it in there, it’s a snug fit.
  2. The second is the smaller magnet part in the gate. I figured this was the best way to do it as this is the bit that gets smashed around more and probably more likely to have water ingress, which shouldn’t matter at all. used a 9 or 10mm drillbit and again just pushed it in.
  3. The final image is the gate closed so you can see that most of the time you can’t see the sensors at all and also this means that it’s completely protected from any rain or the like. This one’s been working for 6 months at least and right through what’s been a pretty wet winter.


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I would want a watertight housing to protect the battery, but either way in a quick-hack situation I’d at least dip the PCB in conformal coating. I think with the vibrations and possible salty solutions on a gate, I’d go with a silicoat:


Yeah not cheap stuff, but IMHO a requirement if you’re storing/operating PCB’s outside.

Really? For a £9 piece of hardware? The one on my front gate has been operating continuously for over 18 months now with one battery change in a ziplock plastic bag (£2 for 100).

Though I do like any excuse to dip electronics in gloop. Makes me feel all engineery! :slight_smile:

Just to revive an old thread. I’ve several aqara sensors outdoors (temperature, motion, contact sensor) and all of the ones in sheltered areas, away from the rain, have worked fine.

The temperature sensor has a battery life of only maybe 6 months since the temperature fluctuations outdoor cause a much higher number of reports back to base. Indoor temperature sensors easily last 2 years on the one battery.

The motion sensors work fine after 2 or so years under canopies and gutters and in sheltered outdoor areas.

However the contact sensors not so much; I installed one on a gate in May 2020 that is very open to the elements and attempted some basic waterproofing using insulation tape. It lasted until November 2020 when it went offline, and an inspection revealed condensation inside the unit. This appeared to permanently damage it because I haven’t been able to reset the device or pair it since then, despite replacing the battery and pressing the reset button. All I ever get is about 20 seconds of blinking blue LED, and nothing. I replaced this sensor with another xiaomi sensor, with still more insulation tape, and it only lasted 2 months this time (it’s been raining basically constantly since November). Same issue - blinking LED for about 20 seconds and no response otherwise.

Thus ends my efforts; I might look at alternative weatherproofing efforts but the sensor in this case has to be very inconspicuous in order to satisfy the aesthetics of the gate… so no ziplock bags or bulky plastic boxes. I’m considering total immersion with a glue gun, or recessing into the wall and covering with a panel. But direct rain definitely causes failures (insulating tape obviously being a lackluster measure).

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Had a temperature sensor sit on the outside frame of my window, not entirely protected but under a roof and it took about 1.5 years before it died on me.

After prying it apart to check if it could be salvaged I noticed water and corrosion on a couple pins of the main chip and some resistors but sadly just drying the board and cleaning it of with isopropanol wasn’t enough to save it so I’m gonna have to buy a new one.
The main point of ingress seems to have been the pairing button which was pointed upwards just begging for some rain to hit it, so if you seal that with some silicone or similar it should hold up for even longer.

My plan for the new one is to coat the board and all components except the temp./humidity and pressure sensors in nail polish and try to seal the button with silicone and see how long it lasts this time. (also gonna move it to a more sheltered spot)

What are you doing with motion sensors under your gutter ? Asking for a friend.

Motion detection for outdoor lights, and security. They are sheltered just under the rain gutters and are facing the garden so they can trigger lights when it’s dark.

Ahhh yes. That makes sense.

How is your long-term experience with that housing? Considering to order that one as well…