ZHA devices intermittently not working. Possibly device limit

I got a ZHA network with 62 devices and 306 entities. The devices are hooked up to home assistant with a sonoff zigbee dongle plus in coordinator mode.

My devices are a mix of smart sockets, light bulbs, led controllers, AC powered blinds and aqara/ikea buttons and sensors. I like to think it’s a healthy mix of ac devices that can act as relays etc for the battery powered devices.

Recently I’ve noticed the battery powered buttons have stopped working. Rebooting home assistant sometimes fixes it. Taking battery out of the button and reinserting sometimes fixes it.

Now my questions….

How can I debug this?

I suspect it’s because I got too many devices… Any way to validate this?

Should I be adding sub devices via the ac powered devices or is that automatically taken care of by the coordinator? Ie ‘add via this device’ button

If you’ve read this far… Thanks! I hope you can help.

Hi there it’s definitely not a limit issue as you can see I have a few and all working perfectly.


Is your dongle attached via a USB 3, if so try the USB 2 port, also it helps to have it on a USB extension cable to move it away from the main box.

When I was first setting up I did find it took a couple of days for the AC powered devices to find the best route back to the controller, then attach the battery powered devices.

By working perfectly, do you notice any latency with that many devices?

At first there was a little, I thought logically about the position of the mains powered devices, for example does it have direct sight of the next jump, are there any walls, etc etc and I do have a few powered sockets where I probably don’t need them just to provide a route through. I have a few more devices now…


I have also found that some do drop out occasionally, but it always seemed to be the same ones, on changing them to a different brand, that seems to have stopped.

I use these now, for sockets and they are very stable.


Hope this helps.

Relative modern Zigbee Coordinator adapter like those based on Silicon Labs EFR32MG21 or Texas Instruments CC2652/CC2652P radio chips can handle around 200 Zigbee 3.0 devices if you have enough Zigbee 3.0 router devices, see:




Try replacing the battery with a new one so not a batter issue (low-battery reporting from battery-operated devices are often wrong so should not be trusted out of hand).

Otherwise the two most common issues are EMF interference and not enough well working Zigbee Router devices with good reception close to devices with issues, so suggest take active actions to avoid sources of EMF very close Zigbee devices (especially for the Zigbee Coordinator adapter) as well as add a few “known good” dedicated Zigbee Router devices.

I highly recommend reading and following all the tips here before even trying to troubleshoot any deeper to rule out those well known issues → Zigbee networks: how to guide for avoiding interference and optimize for getting better range + coverage