Hey OP, you may want to check one of the comments on one of the @tomasmcguinness’s posts:
I’ve got my hands on a ESP32H2 Supermini, here a my results (measured with PPK2):
- 3.3V Input to the 3.3V PIN
- deep sleep TimerWakeup Example from the Arduino ESP32 core
- Board unmodified: 488 µA
- WS2812 removed: 223 µA
- LDO regulator removed: 148 µA
- Battery charger IC removed: 115 µA
- Charger LED removed: 85 µA at the start, 17 µA after 20s (probably due to charging capacitors)
In theory:
- An unmodified board at ~500 µA should give you about 7 months on an 18650 2500mAh Li-ion.
- But, if you remove all these components you can get 2+ years on a 500 mAh AA-sized LiFePO4, which is smaller and safer.
Then why did you get ~2 months of runtime? Assuming all else is good enough (your code, your specific battery), it might be because you feed the board from a battery using the BAT pins. The battery input feeds into the LDO, which is likely not efficient enough.
I did this and removed all these on my ESP32-C6 SuperMini (which is near identical to the H2 SuperMini), as well as the battery LED, and it works. I can connect and OTA update over my $5 Thread Border Router. I don’t have a way to measure the power consumption other than running it on the battery and see how long it goes.
Show photos
I accidentally removed a few more capacitors and resistors but they seem to be non-critical elements.
Thanks to your efforts, I can try with deep sleep now, didn’t know this was even possible. I’ll try and report back the results after a few months.
If you want to follow this path and remove the components:
- Do not use a hot air gun, use a soldering iron.
You might lose the ability to connect and update over USB. No, it works. But since the board can only be powered by the battery, keep the battery connected during USB connection.- You can’t use a Li-ion.
- You won’t have over-discharge protection. You can probably get that by using an ADC pin.