I run the Everstart group 29, with an 80# Minn Kota maxxun. That is the biggest that fits in my battery compartment. Never ran out of juice, even running the trolling motor all day. Using low power, up to 40, a full day will drop to two lights on the charger after an hour or so of charging. Running on 20-30 for a half day, recharge is about 30 minutes.