Zigbee ZP01 Motion Sensor 18650 Upgrade

If you have these low cost zigbee motion sensors that use 2xAAA batteries, they can last a while. However in my case they were in high traffic areas. I had a bunch of refurbished NCR18650B cells. I figured why not.

Background: The sensor uses a Heermicro 65NX SOT23 LDO. The datasheet says its good to 6V input voltage. The nominal voltage of the NCR18650B is 3.6. A fully charged battery is around 4.2V.

I added a BMS protection module to the battery holder to ensure the cell does not go below 2.5V.

I use Home Assistant battery monitor to warn me when these sensors get to around 2.8V, reminding me to charge them back up.

There are 3 back housing options, Flat Mount, Ceiling mount and wall mount. The ceiling and wall mount are set to 33 degrees.

Use 10% infill. Its plenty strong.

You will need some self tapping screws to attach the back cover (No4 6mm Self tapping screws).

The back covers can be attached using double sided tape or there are two 4mm holes for attaching to the surfac