Iota DC/DC converter shorting plug mod
I found I could cut the green wire on the Iota 45 shorting plug and use a 12V relay to engage max charging while the truck is powered.
With the shorting plug out, it trickle charges the 12V battery. With the shorting plug in, it charges at the full capacity, around 14V. Cutting the green wire and putting a 12V relay across it connected to the ignition on signal allows it to only max charge when the ignition key is on.
Previously, I had the Iota set to only trickle charge with the ignition on. Worked great in summer, but with headlights on both morning and night, and traffic backing up on the highway (lots of braking vacuum) my 12V battery went down to about 9 by the time I got home. So I left the ignition key on to charge the battery while I started to charge my pack. I have the Mini BMS system installed, so in this configuration, it thought I was driving and would not shut off the charger. Luckily I was in the garage and heard the buzzer going off before I overcharged my pack.
Rule #1- Never leave the ignition on when charging!