Hey guys,
One final feature I wanted to add (and time had allowed) was the addition of a charge mode. Provided you are using a hall sensor to monitor battery current, this version of code detects current moving in the opposite direction and automatically brings up a charge status screen. Battery charge current is calculated from measured battery amps and a “charge efficiency” constant you can select. This calculated value is added to the battery’s capacity every second. The new screen shows total charge time, measured charge amps, and the current SOC. If charge current goes to zero (or a programmed trickle charge threshold) the charge timer will stop incrementing.
Since accessory voltage is off while the car is charging, an alternate +12V source is required. I used a 12V 1A AC/DC power supply mounted in the engine bay and powered from an AC outlet on the side of my onboard charger. An oring diode is required on this line. I attached mine to a harness which is then soldered onto the LCD board right at the input to the +5V regulator (see pics)
I’ll have the code posted sometime this week.
Here’s a little demo-