oh, I was reconfiguring the two batteries in my truck, lol
pull the starter wire off the main battery and hook it to the positive of the second battery, hook the negative of that battery to the positive of the main battery
then only the starter sees 24v and nothing else, I was kinda worried about it backfeeding through the solenoid wire
you know how the pull in coil is grounded to the M terminal and the hold in coil is grounded to the body, I was figuring that the solenoid would act like a latching relay since the pull in coil would have 24v backfeeding against the 12v on the S terminal but that didn't turn out to be a thing?
I'd charge the battery hooked inline with the starter cable separately with a plug in charger
was gonna hook that battery up to a solar panel but finally ponied up and bought a new starter for it last year