Hello everyone,
I have 2 IKEA Tradfri 5-button remotes.
One of them needs a new battery each 2-3 days.
I found out that the difference between those 2 remotes is that the one eating the batteries uses an innr White&Colour E27 bulb as router.
In a different thread someone mentioned that they connected the remotes directly to the coordinator instead.
How can I achieve this? In the network visualization I see no option to change connection behaviour as ZigBee does this dynamically by default?
Z2M lets you do this. It looks like ZHA does not.
I am thinking you can remove the device you want to move from the router, remove power from your devices that are routers, add the device back when only the coordinator is available.
Not sure if ZHA will reroute your devices to routers after or not.
Find the coordinator in the device list and drill down. Then choose “add device via this device” and re-pair.
That should join via the coordinator initially, but there is no way to keep it there if the device decides to re-route. I don’t know how sticky ikea devices are to their initial router.
The real solution will be to more or less just add more (and better) Zigbee Router devices to your Zigbee network. So simply read and try to follow the tips in this → Zigbee networks: how to guide for avoiding interference and optimize for getting better range + coverage
You should also take actions regarding the advice there about EMF/EMI/RMI interference too.
You can not force a Zigbee device to connect to the Zigbee Coordinator or to a specific Zigbee Router device, load balancing is done totally dynamically. Again, all you can do is add more and better Zigbee Router devices.
It is done fully automatically and you have no contol over it other than adding more Zigbee Router devices and strategically placing them in locations. For more information checkout these:
https://community.home-assistant.io/t/zigbee-buyers-guide/654695
That is not true. While you can initially join a device via a specific Zigbee Router device in either ZHA or Zigbee2MQTT there is no way to force it to stay with a specific Zigbee Router, instead, all Zigbee devices constantly reevaluate its possible connections and should automatically connect to the best Zigbee Router device for it about once every 24-hours.
Thank you for the replies.
I now added both remotes directly via the coordinator.
Let’s see how it turns out. 
In the network visualization they are now connected to nothing anymore but otherwise are working normally.