ESP8266 Community Forum

- Tue Nov 03, 2020 11:25 am #89296 That's indeed nice stuff. The dual mode converters I've seen so far are two in sequence, first boost then buck.

I haven't received my converters yet, so we'll have to wait and see, proof and pudding

- Tue Nov 03, 2020 2:53 pm #89297

Interesting. Totally agree on the LDO stuff.

I don't completely agree with the statement that using a buck/boost will only extend the battery life by a few hours. Using a coin cell that may be the case, but I will be using (preferrably) rechargable AAA batteries and my experience is that their voltage starts to drop very quickly, even if they still have lots of charge inside. So that's why I will be using a boost converter (boost only). I'll have to take care that voltage never excees 3.6 V and I believe using two AAAs that condition is met (as the boost converter can only increase voltage). If that appears a problem after all, I can try to connect both (or maybe three or four) batteries in parallel.

If I can't use rechargables after all, I could always opt for completely drowning normal batteries that have their voltage dropped too far for other uses. I've found out many appliances stop working even if there is lots of charge left, simply because the voltage drops. Some of them don't even work on rechargeable batteries, for that reason. So I always have leftover batteries I can't use for anything else.

I have had good performance using one AA 600mAh LiFePO4 battery to provide 3.3 volt power for an ESP32 door sensor. No voltage conversion or LDO is required. The ESP32 spends most of its time in deep sleep and I have not had to charge the battery in over a year. I do have to remove the battery from the holder (disconnect it from the ESP32) to re-charge it because the charging voltage exceeds the 3.6 maximum supply voltage rating of the ESP32 device.