I've made a few extra modifications to the charger. Installed a solid state relay in the ac line to the fans and coolant pump psu. Controlled directly from the arduino fan output pin. Fans and coolant pump cut in at 20C. Also purchased a 12v 7 day timer on ebay. This is a simple little device with a single NO contact that can be controlled by time or a manual override button on the front. I connected a 4v7 zener across the 10k pulldown resistor on the bms input pin and sent a 12v signal throught the timer and a 1k resistor to that pin. Reversed the logic in software so the charger idles if the pin is low waiting for it to go high to commence charge. Charging is terminated by the timer opening the contact and the pin reverting low.
Full mode 3 communication is now running stable with the charger reading the control pilot signal and calibrating power accordingly. When running in mode 3 the charger enables power by selecting state c but does not begin charging until the timer brings the bms pin high. This is so as to allow battery heaters to raise the pack temperature before commencement of charge. Another option for this would be pack termperature monitoring. That's on the to do list!
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Now, Cole, when you shift the gear and that little needle on the ammeter goes into the red and reads 2000 Amps, that's bad.
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