I am reading what i've found regarding ESP32 on battery and more i read more confused i get

I have this board and today tried to power it with 2xAA batteries using step-up 0.8-3.3V to 3.3V booster. The power led is working but not the board. Tonight ill try to debug why but i gues its brownout detector error

My other option is a 3.7V Lion battery but if use it i must drop 0.4V from it which requires and additional LDO or hacking it with some diod instead.
Please give me some directions, especially if you are using the same board. Or just share your battery setup. ESP32 is widely used iot device and in the same time i cannot find a good blog/tutorial on this topic.