I use a 6volt SLA 12 amphour battery for the bait tank. It works all day(and I mean ALL day!), and provides sufficient flow to keep the bait frisky! The only time I've ever had a slight problem was in the middle of summer when the surface water temp was a lil too warm. I use a separate 12volt battery forthe FF. This works well because the bait tank is behind my seat and the 6v battery goes in the seatback pocket! The 12vv. battery rests in the bow in the milk crate, right in front of to the FF! When I tried a 12 v. battery on the bait tank, it was like putting the dines in the Niagara River! They all died very quickly! If you shop on line, here's a good link for batteries and chargers! I've done business with these folks! I'm not sure how many amphours you need for the FF battery. It doesn't draw energy like the bait tank pump! Good luck!
Piranha
6 Volt 12 Ah Sealed Lead Acid Battery: BatteryMart.com
12 Volt 7 Ah Sealed Lead Acid Battery: BatteryMart.com