Powering by li-pol battery

Hi all,
i want to use li-pol battery (3.7V) to powering the core module - what is the best way to connect it?
i know its possible using battery module with step-down (too big) or USB connector. any other solution when i dont want to use extra step-down module?


Hi, I’ve tested few solutions and without LDO or Step-down converter it is not power efficient enough.

You can solder to the +5V USB input power rail but this also powers the FTDI which increase consumption from usual 15uA to 1.5mA. So for long time running projects this is not usable.
The only way is use as you mentioned Battery Module or LDO or DC/DC with low quiescent current and output voltage 3.0V which you connect to VDD pin.

Thanks Martin
understand… do you have suggestion to small step-down module?
i found this one https://www.gme.cz/miniaturni-menic-napeti-1-8v-5v-na-3-3v-100ma … what do you mean about it - it’s 3.3V?

3.3V is ok, but there is no datasheet where you can find quiescent current (vlastní spotřeba)
Chiptron lately went through this rabbit hole. Here are some articles I’ve found: