I’m hoping to find a way to use a battery backup to keep the AutoPi running, even after the car’s battery drains. Additionally I’d rather not run the AutoPi off that, since I think it can damage it over time.
I already have the Blackvue B-124 battery, which powers my dash cam. I’ve been thinking I want to daisy-chain another battery, then power my LTE hotspot, along with my AutoPi.
Is there a way to power the AutoPi via GPIO, or via USB? I know I’ve seen the warnings against this, but curious if there’s SOME way. Otherwise, I’d have to splice into the OBD2 cable, and install diodes. Allow 12 to come in from the car battery, and ALSO from the battery pack. This would make the power-down-at-voltage function unreliable, but ideally my AutoPi can run 24/7.
Note: I’d love for the AutoPi to still be able to see the actual vehicle battery voltage, and run the RPi3b+ off of USB/GPIO/etc, but not sure how well that would work. Perhaps some diodes could be installed to power the RPi GPIO separately.