SmartThings Multipurpose Sensor Battery (How To Replace and More!)
After the honeymoon phase of setting up your smart home is over, there are some maintenance tasks you’ll have to do to make sure your automations continue running smoothly.
One of those tasks involves changing out old batteries from your smart devices.
SmartThings Multipurpose Sensor Battery
The SmartThings Multipurpose Sensor uses a single CR-2450 battery. It needs to be replaced every 6-12 months, on average (mine died after 9 months). Replacing it only takes about 2 minutes and requires a small, 3/32″ flat head screwdriver which is used to force the casing open, exposing the battery.
How to replace the battery
Replacing the battery is pretty straight-forward, but it does take just a little bit of patience.
Before you get started, make sure you have a small, flat-head screw driver handy. You’ll need this to pry open the white casing.
Once you’ve got the casing off, it is as simple as taking out the old CR-2450 battery and replacing it with a new one.
Then just slide the white casing back on until you hear it “click” into place.
Here is a video showing just how easy this process is:
Which Multipurpose Sensor do I have?
SmartThings is currently on its third Multipurpose Sensor model.
Here’s a list of all the sensor versions:
| Old model | 2015 model | 2016 model | Current model | |
|---|---|---|---|---|
| Model |  |
 |
|
 |
| Battery Type | 2 x AAAA | 1 x CR-2450 | 1 x CR-2450 | 1 x CR-2450 |
Luckily nearly all of these SmartThings Multipurpose Sensors use the same battery type (CR-2450). (If you have the old model, you’ll need two AAAA batteries.)
That said, the new model (rounded) gets better overall battery life and provides more precise measurements. due to sensor enhancements.
That’s not to say the 2015 & 2016 models are bad. If you have one, keep it and use it until it stops working.
Otherwise, if you’re buying one now I’d definitely go with the latest model. Go ahead and check the price of the new model on Amazon here.
Battery type
As mentioned previously, the SmartThings Multipurpose Sensor uses a single, 3 Volt CR-2450 battery.
The CR-2450 typically has a rated capacity anywhere between 550 and 620 mAh.
mAh means “milliamp hour” and is a unit that measures (electric) power over time. It is commonly used to measure the energy capacity of a battery. In general, the more mAh, the larger the battery capacity and longer the battery life.
It’s not surprising then that the lower mAh CR-2450 batteries typically cost less than those CR-2450 batteries with a higher mAh.
The CR-2450 holds its power for about ~8-10 years in storage, so if you’re able to get a deal on a pack of them I think it’s a good idea to buy in bulk.
Especially if you use multiple SmartThings Multipurpose Sensors through-out your home, like I do. Or if you have other electronics that use the same battery type.
One great deal on CR-2450s is the EmazingLights 20 Pack on Amazon. These batteries cost less than 10 bucks and have a mAh of 600! You can check the price on Amazon here.
Battery life
SmartThings reports an average battery life of between 6-12 months for it’s Multipurpose Sensor.
In my experience, this is just about right.
I bought two of these sensors almost a year ago now. One of them died in 9 months and the other is stilling working, over a year later.
The one that died does have routines attached to it and gets used often. For example – “turn on bathroom light on low when bathroom door is opened past 11 PM”.
The other Multipurpose Sensor is simply being used on my basement door and rarely if ever triggers an alert (when the door is opened past 1 AM).
So it makes sense that my bathroom door one died first.
Something else worth noting here is that the Multipurpose Sensor battery life percentage read-out is usually flat out wrong.
SmartThings acknowledges this on their website: “it’s not uncommon for battery levels to underestimate the life of a battery at 30-35% less than what it actually is“.
This is because the battery readings measure voltage, which inherently fluctuates throughout the cell’s lifetime.
So all of this is to say, don’t worry about it if your sensor says it has “10% battery left”. In all likely-hood it has nearly 50% or more battery left.
I would only think about replacing the battery when it says “1%” remaining, or when it dies of course.
Multipurpose Sensor use-cases and ideas
What’s great out the SmartThings Multipurpose Sensor is its versatility.
It can measure open/close, vibration, orientation, angle (tilt), and temperature. It packs a pretty big punch.
All these “different” sensors mean a lot of different possible uses!
Here are some of my favorite:
Door
This is probably the most common use-case and it’s the one I use the most. Placing this sensor on your door allows you to do a few things.
First you can simply monitor whether that door is opened, or closed. With that information in hand you can then trigger a series of automations.
For example: “If my basement door opens between the hours of 1 AM and 5 AM, turn on all lights and play music from Alexa”.
This is a great alarm for intruders or even for kids who might be tempted to leave the house late at night.
Window
Not a ton to add here, as adding this smart sensor to a window offers a lot of the same functionality as adding it to a door.
The idea of course being that if someone opened a window during a certain time or day, you could get an alert or trigger automations.
What’s unique about this use-case is the ability to leverage the vibration sensor.
Let’s say if instead of opening your window, an intruder shattered the glass.
That vibration would still set off the sensor and therefore your alerts/automations.
Washer/Dryer
You can also use the vibration sensor to monitor your washer/dryer cycles.
Let’s say your washer/dryer is all the way in the basement and you don’t want to have to remember to set a new alarm every time you kick-off a new load of laundry.
Simply attach a Multipurpose Sensor to the washer and/or dryer and have it trigger an alert when the vibration stops.
This way there isn’t any guess work as to whether or not your load is ready to be moved from the washer machine to the dryer (for example).
Mail-box
If you’re like me, you probably check your mail-box a couple of times a day – my mail man is pretty inconsistent with his delivery time.
To avoid this you could simply add one side of the Multipurpose Sensor to the inside door of your mail-box and the other on the inside of the mail-box itself.
This way anytime the mail-box door is opened, you’ll get an alert “You’ve Got Mail!”.
Pretty sweet.
The possibilities are truly endless and you can get pretty creative with it.
If you’re interested in even more use-cases for a variety of smart sensors, check out my post: 12 Different Kinds of Smart Home Sensors (Everything You Need to Know!).
Conclusion
The SmartThings Multipurpose Sensor uses a single CR-2450 battery which needs to be replaced every 6-12 months, on average (mine died after 9 months).
To replace the battery use a small, flat head screwdriver and force open the casing. This only takes about 2 minutes.
There are endless awesome ways to use the SmartThings Multipurpose Sensor in your home.
What are some of the ways you use yours? Leave me a comment down below.
