Just a note, I’ve switched to an STC3100 “Battery monitor IC with Coulomb counter“. The LTC2942 became unavailable and turned out to be more expensive.
I’ve got the basic driver here – the device driver reading the registers is here —https://github.com/neilh10/STC3100arduino
A device manager that can provide power consumed in mAhrs is still wip.
I’m using it with an enhanced RS485 power board that supplies power directly to the 4V to 12V booster – and it can supply a continuous 1.9W.
This a new board, and if anybody wants one they should let me know this week so can be included in a manufacturing build.