Govee H5101 Hygrometer Case

The Govee H5101 is a digital temperature and hygrometer monitor.  It displays the current readings on a LCD panel and can share the readings, including history via Bluetooth to a smart phone.  The unit is power by a CR2450 button battery mounted internally.

I found that the CR2450 battery has a life of between 3-6 months, depending on battery brand quality.  Too short a life for my liking, hence this project.

The goal was to handle the battery replacement/recharging yearly, or less frequent.  My solution is to replace the CR2450 disposable button battery with a 18650 rechargeable battery.  Depending on battery quality (capacity and self-leakage), the 18650 battery has up to 5 times the CR2450 capacity.  I'm expecting 18 months to two years between charges.  Let's see ...

The meter is readily available for purchase.  I purchased my module through Amazon for US$19 (for a pair) from here:
https://www.amazon.com/Govee-Temperature-Thermometer-Hygrometer-Greenhouse/dp/B08CGM8DC7

The 18650 battery is physically larger than the CR2450, so won’t fit the existing H5101 case.  My solution is to incorporate the H5101 and the 18650 battery into a new case.  The case is 3D printed and allows for an 18650 battery holder, too (if you so desire).

Electrically the 18650 battery can deliver up to 4.2V.  I avoided putting unnecessary stress on the H5101 by including an in-series diode, dropping the voltage slightly and adding reverse battery polarity protection as a bonus.

My print is made in PLA+ 1.75mm 3DFillies silk white filament, with 0.2mm layer height and 25% infill on a PRUSA I3 MK3S printer.

I hope you can find this design useful, too.

Remember to leave me some feedback or even a tip to keep me enthused to make more of these drawings.