Which Battery is best?

[FishStretcher]

The biggest things to limit starting motor performance are the starter, cable connections, cable diameter, cable length, and the battery. If the battery is new, and fully charged regularly, then I think the type is mostly irrelevant. Certainly the outboard wasn't engineered to work with an AGM but not a flooded battery. And for recreational use, I think overcharging is far less likely than undercharging. And letting an undercharged battery sit is bad for life. There are only a few manufacturers but lots of brands. And generally capacity is related to the amount of lead and not a lot else. Starting power is related to plate surface area. Get the newest flooded battery you can- check the date code. And verify the cables and starter are in good shape. I have had more expensive batteries quit than Wal-Mart ones.

[bigeasy1]

I've used Interstate batteries for more than twenty years with no problems.Currently,on my Tsunami,I'm running two batteries,one is a grp 24 marine cranking battery and the other is a grp 27 deep cycle.These are in conjunction with a perko switch.

God, I'm terrible with my batteries,I rarely check them,and I keep saying that I'll switch back and forth from day to day,or that I'll always run the deep cycle when I'm trolling with the elec.downriggers,vhf.radar, etc all on.The truth of the matter is I forget,so god only knows how many hours are on each one.
Been 6 years now,they still test good,but maybe one of these days it's going to be time for a couple new ones.
I think I'll have to put a big sticker next to the ignition switch that reads,

" HEY! STUPID, CHECK THE BATTERIES"