Iris Motion Sensor (2nd gen, 3326-L)

So finally got my butt in gear and got a tester. One battery registered . 99V and the other didn’t register when I had set to 20v and said 16 when I did 2000 mv. The really low one has been in the device for 16 days since it stopped registering. The one with . 99 I took out about 1 day after it stopped.

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What would low voltage be for a 3V? I just replaced another Iris sensor battery (different device) and the old battery was 2.63V. It registered 11% on ST but was acting up and registering motion that I don’t think was real so I replaced the battery.

If my memory serves me correctly, which it probably doesn’t… but I believe ST see a 2.7 as the low end of the battery life.

Maybe @JDRoberts remembers what that range is.

I had a battery reading 1% yesterday. I swapped it out and just threw it away. It was the original battery and was about 2 years old…

I hate this battery issue for everyone, those things are not cheap at all.

On my multimeter, a new CR2 battery like the one I use in my Iris sensors registers around 3.2V (with my multimeter set to 20V DC). By the time it gets close to 3.0, it’s practically dead. I don’t recall what exact values correspond to ST’s battery percentage reporting, but lithium batteries don’t decline in voltage in a linear fashion–see, for example: This makes it difficult for the DTH to predict remaining capacity based on voltage, especially since it plateaus for a bit after a slight initial dropoff and a sharp final dropoff if it’s even still usable at that point. I’d be hesitant to rely on ST’s reporting given this difficulty.

(My multimeter might be reading this all a bit high; I’m not sure how well calibrated it is for these voltages—certainly appears to be a bit higher new than on the Energizer chart above—so if you have one you may want to test when new and “dead” to compare.)

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Does anyone know if this works for the 3326-L2? These are currently on sale at Lowe’s for $15, and I’d like to buy several, but I want to ensure they work with SmartThings first.

If what works? They work out of the box now.

This thread seems to be about the 3326-L model.

There is also a 3326-L2 model, which I don’t see mentioned in many places.

I’m currions if the -L2 works in addition to the -L. I’m guessing the answer is yes, since it seems to be a new version of the same sensor, but I’m not sure if there’s an important difference for SmartThings compatibility.

They’re the same sensor, only difference is the packaging

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Well, a couple days ago had another one go into meltdown mode and start registering false motion every minute or so. Replaced the battery but then sadly another for the waste bin.

EDIT: Did it again last night (couple days past a month) and killed the battery, so time to order something else. Given how highly people rate these, I wonder why mine are having so much trouble. I did find my Google WiFi causing problems for a Bosch motion sensor, but that was when it was super close. When I moved it away it was fine. This Iris one isn’t that close.

I just got around to replacing the battery in a problem sensor, taking notes this time, and it died after 6 days. I read up on a few of the recent threads, including one about updating Iris device firmware via Iris hub, which prompted me to check my sensors’ firmware in the ST IDE.

I have 5 sensors, all purchased within a 1-2 month period (when Lowes had them on clearance last fall). One of them eats batteries. All are running the same firmware, 0x1C005310. However, 4 of them have “N/A” for “last updated”, presumably meaning it shipped with this firmware. The problem sensor says it was last updated 9/5/18 (same day it was added to the hub).

I think I’ve seen the suggestion before that the battery problem is linked to firmware, but my interpretation of this data point is that the problem isn’t the firmware release, but either ST’s copy of that firmware or their update process. I don’t think I’ve previously seen the blame placed there, so I wanted to throw it out there and see if anyone who has both good and bad sensors finds the same thing.

Edited to add: even if this could be confirmed as the cause, I can’t imagine anything could/would be done to recover those sensors - it’s not likely that Iris is releasing new firmware (RIP). Since the bad sensors already have the target version, would it even be possible to overwrite it with a new “good” version? And if it was, would ST bother to devote resources to supporting an obsolete device? @tpmanley, would you care to comment on the technical side?

@MarkTr, the FW update process in Zigbee is standardized so I don’t expect that to be the issue. The FW we release is provided by the manufacturer so it should be the same thing as anything they release in a manufactured product, although we have no way to confirm that. Have you tried factory resetting the device and joining it again (no need to remove from your SmartThings account before you do this)? I’ve seen cases where the new FW caused excessive battery drain that would be fixed by a factory reset. To my knowledge we’ve always caught and corrected those issues before they were released but it’s worth a shot. If that doesn’t work you can PM me your info and I can take a look to see if I can determine what’s causing the battery drain.


If you guys get anywhere, please report back. I had one move into the <1 week dead category and after 3 batteries I threw it away. I have another that is now in the ~2 month dead range so watching that one. I had another one go into the <2 week dead range but was under return window so got a new one.

Thanks Tom! I reset the sensor last night (with a new battery) and it reported 89% after about half a day. I’ll see where it is this evening and send you a message if it’s still dropping.

Dead after ~5 days. Sending you a message Tom…

I know this is 4 years old, but I am trying to achieve this exact same goal (decimal temperature reporting) with the same sensor. When I try to create a new DTH from the code here, it gives a bunch of errors. Seems maybe to be related to unintended formatting from copy/paste. Any chance you still have this code working? Is there a newer/better solution?

I’m also going to jump in here. Anyone else experience the “0% battery remaining” issue?

I have Iris motion sensors all over the house. Well over 50% of them consistently read 0% battery remaining. This is regardless of battery swaps, and they work perfectly fine otherwise.

In the list attached, all are Iris Motion sensors, all work fine, and the Kitchen and Living Room were both replaced with fresh, 3.26v+ batteries last night. Ironically, Kitchen’s now reading 100% (unsure how long that’ll last) and Living Room remains at the 0%.

I have almost 30 of these motion sensors, and haven’t experienced anything like what you are seeing. Are you using any custom DTH’s?

It also looks like you’re suffering from the latest Classic app’s (v2.19.0) bug where tiles aren’t displaying icons properly. You’re missing the icons in the Main tile and Refresh tile.

I have about 10 of these motion sensors and another 25 of their contact sensors. I don’t see that problem. I’ve been using regular CR2 batteries up until now (I’m just switching over to rechargables).

I also use the Device Monitor smartapp to only report on devices that have low battery and have not reported events for 25 hours.

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Late reply, but I believe the culprit was that I was using incredible poor quality rechargeable batteries. As soon as I switched to regular one-time use batteries, not only do they last like 5x as long but they work better, especially battery accuracy.

@jlv those are actually the batteries I was using. Did they cause an issue for you too?