Hi David,
What a project!
A couple questions that will hopefully help everyone with future replies:
- What chemistry is the battery? SLA, Lithium Iron Phosphate, Li-ion cells? The key part here is multiple cells and the usable voltage range - a LiFePO4 battery sometimes has an inbuilt BMS to handle cut-off
- What kind of environment are they running in? A shaded enclosure like a picnic BBQ?
Back to the project…
Unfortunately, there isn’t a PiicoDev module but a solution is very simple(and breadboard-able)!
A voltage divider can be used to divide down the voltage to a <3.3V level for the Pico’s ADC
(From topic: Makerverse USB-C LiPo Charger (CE08374) - #19 by John219336, though you’ll have to use different values for a 12V battery.)
The second battery is also quite easy, schottky diodes from the positive terminal of the battery into the Vsys pin will preference the highest voltage supply (USB, 12V battery or LiPo)
Keen to see how it goes!
