Hi Johan,
Unforunately Jaycar doesnt seem to have a spec on the current usage of the board, we could speculate using the datasheet from Espressif although to get a much more accurate estimate it would be best to measure the power usage using an accurate power meter such as the Qoitech Otii Arc. Then picking your battery is as simple as average power draw
Since a LiPo’s voltage drops as it discharges you’ll need a converter to step it up to a usable voltage for the breakout board you are using, I’d recommend one of the powerboost modules, the lower the quiescent current the better
Measuring how much current the system uses at each point is essential for choosing your battery. Sam wraps up the whole topic perfectly in this guide,
Without being topped up a new variable comes into play being the internal discharge of the battery, luckily LiPo’s have a relatively low internal resistance.
Turning on and using the WiFi radio consumes a lot of power, if you can get away with it storing the time/button press status and uploading a whole day/week at once will let you extend the battery life even more.
I won’t be able to spec a specific battery that will be able to last X(without all of the data) amount of time but using the guides and advice linked above you’ll be able to navigate through the maths and select one!
PS: there are lots of other forum topics here that discuss something similar, I’d take a look around and uncover some other nuggest of information, here’s a few good ones:
Liam.
