Need temperature/humidity sensors for cigar humidors. Considering the:
Mini NodeMcu ESP8266 Module Type-C USB ESP-12F
Diitao 6PCS DHT22/AM2302
Taken Garden Solar Light Batteries, 4 Pack 18500 Battery 3.2v LiFePO4 Rechargeable Solar Batteries1000mAh
Looking for long battery life and accurate humidity.
Any ideas?
You can get up to 3500mah 18650 batteries. Quality matters for capacity. Best to stick with buying reputable brands (Samsung, Panasonic) from reputable stores.
Examples
Picking an esp32 which is optimised for low power is key. As is implementing a deep sleep cycle between measurements.
Alternatively, try wireless ZigBee or ble sensors Aqara, Xiaomi). Cheep, cheerful, long life (not sure about accuracy, could potentially be calibrated).
Wasn’t sure what to use, 18650 or 18500 batteries and what battery holder to use.
Currently using Yolink temp/hum sensors. You can calibrate them but they are so off that you run out of adjustment. I use Boveda humidifier packs for calibration.
For what it’s worth:
The best thing that works perfectly here and after trying all sorts of things:
D1 Mini Pro, but this one with battery power: click.
With this simple holder: click
Connected with this 2P PH2.0: click
D1 Mini with battery shield may also work but I have had many failing such shields.
Set up with deep sleep in ESPHome.
Use it for BME280 temperature/humidity/pressure sensors.
Runs over 4 weeks on one 18650 charge
with a deep sleep time of 15 minutes and wake time of 20 seconds. Must have much longer battery life with longer sleep time.