I have an update for those who experience the pairing issue on the battery backup version.
Let me re-iterate what issue we are talking about. I can reproduce an issue where the module have difficulties paring. By share of luck, I can reliably reproduce the issue especially when there is no other repeater around. This issue may not show up in house with enough repeaters.
I tracked down the issue to a bad batch of linear voltage regulator. It is due to bad Linear Voltage Regulator.
I have tested replacing a couple of the modules. I can pair with hubitat hub with no other repeater around.
Here is what we can do. If you would like to send your module back to me, I can replace the voltage regulator. Please PM me if you like to do this.
This part can be replaced easily if you are handy with soldering iron. This is the part MCP1702. You can get them for $0.40 shipped free overnight from arrow electronics.
This has been very frustrating for me and perhaps everyone who got these modules. However, a bad batch of electronic parts do happen from time to time. In addition, the issue is not just a dead module which I can take care of it before shipping out. They do work when you have enough of certain repeaters in the house.
I apologize for the inconvenience. I hope it is one of small hiccup toward building the best modules for everyone. In perspective, when we are over this hump, you will have a module that can help you monitor your room, help repeating your Xiaomi devices and have very high up time. This is unique as far as a Zigbee sensor available to all of us.