Sonoff contact sensor battery issues

I am on C7 hub. All my zigbee contact sensors are from sonoff. They all work well, except one. This one, discharges the new battery within a month. Is there anything I can troubleshoot? Or the only solution might be to throw it away and buy a new one? Maybe this was a faulty hardware piece?

My device is on the same floor as my hub.

Pair it again to the hub (without deleting it), while using a fresh new battery.

Does it report the battery level regularly?

Is it placed in a location where the signal could be weak, resulting in frequent rejoins to the Zigbee network?

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yes, i have changed battery many times now, and everytime i have to pair it back. At that moment, it shows battery is full.

How can I check signal strength for this device?

Also, I just checked a few mins back, and was able to re-pair it, without changing the battery. Any reasons this one device might be falling out of pairing frequently?

Answering this question would be helpful.

The device is on the same floor as the C7 hub. There is no wall in between, but think of a L shape, where the hub is on one end, and the sensor is on the other end of the L. Walkable distance is around 32 ft between the hub and sensor.

If you are willing to experiment and spend more time troubleshooting it, you can try the Tuya Zigbee Contact Sensor++ w/ healthStatus driver. It will not make it work better than the stock driver, but will provide some more detailed statistics that could help to understand where the problem could be.

Oh will this driver work with my sonoff device? Nice, I didnt know. Let me change the drive of two my my devices.

in the meanwhile, here is the graph. "main door" is the device which falls off, or discharges frequently. "back door" is the same brand of sonoff contact sensor which has been working flawlessly:

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My Sonoff contact sensor has been sitting in a drawer for the past year. I wasn't happy with it, but at the moment I can't remember why... :thinking:

I just switched two of my contacts sensors (good and bad devices). Which stats would you want me to look at?

do you have recommendation for any other brand zigbee contact sensor?

Third Reality was always solid for me, though a bit chunky. But regular batteries gave it great life. I've since replaced that one with a wired reed sensor.

If still available around Ebay, the Xfinity Visonic XHS2-UE sensors are also nice - I use several around the house and they've been very reliable.

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Which stats would you want me to look at?

monitor these two stats :

  • rejoins counter is increased every time the device re-joins the Zigbee network (because for any reason the connection has been lost)
  • outOfSync counter is increased every time when the contact state (open or closed) is polled and was found to be different than the current state - this usually means the state changed when the device was offline... You need to switch on the 'Poll Contact Status' option to have this statistic availabel. Polling of the contact state happens any time when something is received from the sensor - usually a battery report.


I avoid recommending particular devices - whatever works in my environment, may not work well for others. As an example - I have a lot of Aqara contact sensors which have been rock solid for years. However, a lot of other users have serious problems with them dropping off the network,
I started with Aqara (and they have the highest WAF !), but all my new contact sensors are Tuya.

wow! These stats should be part of every driver/device!!

Just in case you want to switch or are looking for more. I picked up 20 of these after several power users and others recommended them here on the forums. The seller I bought from no longer has any available. I paid just over $4 each. They have been rock solid. Others mentioned the battery life is amazing. I've only had them about 7 months but all batteries are still showing 100% with some relatively heavy use. I found this seller, about $3.50 each. You can't go wrong with that price. Well, almost can't go wrong.

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IKEA's new line seems to be gaining popularity. Haven't tried any yet myself, but the 365 day return policy should ease any qualms.

Door/window sensor, smart/white


I had set this driver for two of my contact sensors "back door" - which stays connected and has no issues, and 'main door' which is the one with issue.
Over the last few days I noticed that both of them had few "OutofSync" count. I guess that is not a big issue? But, the "back door" had 0 rejoins, while the "main door" had 4 or 5 rejoins. 2 days back, the main door again dropped and I had to repair it. I have now moved one of my repeaters quite close to this sensor to see if that helps.

Something got broken in the ouOfSync code logic in the last driver version... : (
Please wait for a fix.

Hi, just a gentle followup. Did you get a chance to work on the fix yet?

Sorry - honestly, I forgot about this... : (

I have now paired my eWeLink * model: DS01 contact sensor to my dev. hub and will be monitoring how this device behaves. It is configured to report the battery status every 2 hours. I expect with the battery reports to be able to poll the contact status (open/closed), and if the polled contact status is different than the current state of the contact attribute - the outOfSync counter to be increased, and the state to be corrected.