I'm setting up a set of downriggers. Do you guys like to power them off the non-engine-start battery? My understanding of ocean salmon trolling is I'll keep the motor going on the troll, and no real engine-off drifting in this particular fishery, so can't see specific need for them powered off bat1 or bat2 only. I'm new to this equipment and ocean trolling using them, so asking. Thanks in advance.