Here's a 3D printed case to use AAA batteries with the ST motion sensor (now for the multipurpose sensor too!)

For those of you who might be interested, I’ve created a 3D printable case for the 2015 SmartThings motion sensors that uses 2 AAA batteries instead of the a single CR2450 button cell. This provides 3x the capacity at a much cheaper price, so IMO it’s totally worth doing it if you -like me- hate replacing those costly batteries so often, specially after the last (awful) firmware upgrade that made these sensors drain their batteries even faster than before.

It might work for the 2016 model too, but I don’t own any so can’t confirm. Please let me know if you try that.



More details and pictures in the thingiverse page:


That’s just awesome. Are you willing to sell the case for some of us that don’t have a 3D printer?

That’s a great design. Do you plan to make it for the multipurpose seniors too?
I have bien lazy to design such adaptation but one thing I noted when I made the spacers ( is that within a year, the PLA breaks easily.

What quality of filament are you printing with?

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My printer is not that great nor fast, so not really, and it wouldn’t be cost effective at all, specially considering shipping expenses. I’d recommend you to find someone in your area willing to print it for a fee. In this website you can do exactly that:


I’m using PLA too for pretty much everything I print, just because it’s a lot easier to print with than say ABS. I have PLA parts all around my house for all sort of things, including spacers for the open/close sensors, and so far they’ve been perfectly fine. If you’re using them outdoors though then I’d certainly expect the PLA to degrade quickly and would choose ABS or something else.

As for making a similar case for the multipurpose sensors, probably yes. I have a bunch of those and they are pretty reliable (unlike the motion ones), so I intend to keep them going for a long time. Most likely that case would need to be a little larger than the original though, but it should be doable.

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I found the PLA is breaking on the clips part, even on indoor usage: they are flexible at the begining or when the temperature is above 25C but over time and lower temps like now, they become more rigid and break easier when I push them too much. I was considering using either ABS or nylon. But then… lazy me… I didn’t spend time on it.

Just ordered 3 of these on 3d hubs for £13 delivered. Many thanks for the design. Hope you manage to get the multisensor done too.

Thanks again for sharing.

I found the PLA is breaking on the clips part, even on indoor usage

Ah, for parts that need to be flexible that could be the case. I don’t think I have any like that.

Hope you manage to get the multisensor done too.

It’s in progress :slight_smile: it’ll take a while though because it takes several prototypes to get it right, but I’ve learned some lessons from designing for the motion one. This case will need of a custom backplate too, that’s for sure. There’s just no way to fit the AAA baterries in the dimensions of the official case, it’ll need to be a bit wider.

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Small update: I have completed the design for the multisensor but unfortunately testing has shown that the AAA batteries produce interference to the sensor’s antenna, so it often fails to send open/close events to the hub. I’m going to have to change the layout so that the circuit sits on top of the batteries rather than underneath.

Apologies for not giving an update sooner. Real-life™ events are limiting the time I can spend on this sort of hobby. Nonetheless I’ve had the redesigned sensor housing for the multipurpose sensor ready for quite a while, but I never got around to actually upload it to Thingieverse until today. So here it’s, enjoy it:

I’m now running all my ST sensors on AAA batteries. So far so good, but it’s only been a couple of months, so it’s too early to give some battery life stats. The new firmwares pushed to these sensors on September 2018 however do make them report the battery level differently, fluctuating a lot more. So it’s normal if the sensors report 100% battery for only a few days and then start going 80%, 60%, back to 80%, etc. This is what I’ve been seeing at least. I’ve also had a sensor that was still with the CR2450 run on reportedly 1% battery for a full month and still work fine.


For those without 3D printer go to this link and talk with @bamarayne as he will print and he does a great job and dosen’t seem and is quite reasonable.

2 of these in ABS were just $20 shipped from 3D Hubs, but it looks like they changed their policy and now require a $100 minimum order. :frowning:


Thanks for this design! Someone I work with was able to print it in PLA+ for me. I’ll be mounting it on the inside of my garage door, so I’ll see how the battery life compares.