Hi Pix,
They are interesting solutions but not quite what I’m looking for.
More details below….
Hi Liam,
This is for the 12V Battery monitor project previously discussed.
In Summary, my project uses two Pico W’s each with LoRa Wan modules.
The wifi is not actually in use at present but I saw something on YouTube that indicates the On board led uses the wifi pins.
The hand held device has a 4 digit LED display.
I have managed to get it working quite well. The device at the monitoring end runs directly off the 12v battery that is being monitored so that should have plenty of power but I don’t want to put a significant drain it say over a couple of weeks. I have a stackable RTC that I could use to put this device to sleep during the night.
On the display end device I think I have done ok by putting the device to sleep. I can use a button on a GPIO pin to wake it up and a second press while it’s awake to request the voltage. Once the result has been displayed it waits 30 seconds for an additional request or it goes back to sleep. A flashing led indicates waiting and no led indicated asleep.
Now I wish to optimise things where I can, but I need to be able to measure the results of the changes I make.
I’ll go check out the link you posted.
I have also been wondering if I can use a spare pico to build a monitor the power usage during project development.
More learning required 
David
PS The Qoitech Otii Arc looks fabulous but outside the hobby budget.
