Battery for autonomic CubeCell AB-01 (AB-02) and sleep mode

#1

hello

there are a lot of threads in this forum about power consumption of AB-01 device in sleep mode.
it seems there are some issues with board in sleep mode when it powered from battery via Vbat connector - JST 1.25.
These issues related to big current in sleep mode when you power it from battery with more that 4v which is usual for LiPo batteries:

image

on the other hand - there is variant to power the board via 3.3v pin and with this way it possible to have about 4uA of power consumption during sleep mode.
So I decided to check to use LiFePo batteries which has normal voltage 3.3v and connect it to pin 3.3v on AB-01.

Or, for example, is it possible to use supercapacitor to power the board?

Anyone tried this already? Maybe there are some issues with using such power source with Cubecells?

#2

I checked AB-01 v1.2 with LiPoFe4 battery like this:
https://pt.aliexpress.com/item/1005004936921033.html?spm=a2g0o.order_list.order_list_main.64.2ed6caa48kVmCs&gatewayAdapt=glo2bra

battery has 3.3v
I connected it to Vdd pin and receive 4.4 - 4.5 uA in sleep mode.
if I connect it to Vbat JST connector - 10.5uA

So I still wonder - why power consumption in sleep mode on this board is about 40uA when I power in via Vbat JST connector from LiPo battery 4v?
all details I stated here and here

Is this some bug for ver 1.2 boards? Can it be fixed somehow?

Sure it is possible to use LiFePo4 batteries via VDD pin and consider good power consumption in sleep mode.
But how to charge this battery from solar panel? How to measure the battery level?
Both task can be easily fulfilled if you power from Vbat JST connector - but! in this way it can drain battery very fast.
So this is kind of dilemma…
I ask for a competent answer from the developers of the board and from everyone who may know something about how best to proceed.
Thank you!

#3

The charge chip is not setup for a LiPoFe4, it will over charge it which mostly won’t end in some sort of energetic event, but will certainly kill it - they can only take up to ~3.7V