Battery Size

[MJBaldwin]

Just wondering what size battery I should buy. I bought this 14' boat that has a 12v 36 lb trolling motor (im looking to upgrade to a 40lb) and has a 83' evinrude 35hp with electric start.

I bought it with a dual purpose battery 625 marine... it has been garbage since I bought it wondering what cranking amps I should buy and if just a deep cycle would work.

I also run a depth finder, lights, and bildge pump off it.

[bobbymalone]

the biggest capacity battery you can fit your boat.

Any chance you can fit two? I run a deep cycle for my trolling motor and depth finder in the front and a marine starting battery for to start the motor, lights, finder, bilge, etc.

I've got a 17 footer though and it was built for that sort of set up.

[Northlander]

27 series would do you well.

[MJBaldwin]

Northlander-- when you say 27 series what type of MCA or CCA does that one have? I havnt heard the term 27 series before.

[MJBaldwin]

I figured out the 27... Would I be better of doing a dual purpose battery or a deep cycle batter?

Thanks again

[raymondk]

go with the biggest deep cycle you can go with measure your area where your battery goes if you have to get a bigger battery tray don't go with a dual purpose battery your 35 hp motor doesn't take to much to turn over I have been doing this for years with this setup.

[Walleye Guy]

If physical space isnt an issue, buy a series 29 deep cycle battery and battery box. You can never have too much battery capacity. Yeah, 29s are heavy but you will be glad you had the extra amps when you need it. Most boats have a compartment that limits the physical size of the battery. My Lund holds three 27's and I wish I had room for 29s.

[Cheers]

I think the biggest consideration should be whether or not you can rope start the 35hp. If not you need 2 separate batteries

[BobT]

Based on battery types and design if you want to use just one battery your "best" solution is a dual purpose battery with the highest reserve capacity you can find. I've gone into the details about why this matters a few times over the years but in a nutshell the dual purpose battery is better suited to handle the high current demand for starting your outboard while having the reserve capacity to handle running your electric for extended periods of time. A starting battery is designed specifically for what it's name-sake implies but is not suited for low current deep-cycling. A deep cycle battery is designed specifically for low-current loads and repeated deep-cycling but not suited well for high current loads such as starting your outboard.

[MJBaldwin]

I never see very large dual cycle batterys has been my issue. I do have a pull cord on my evinrude. The battery actually tested as nothing and it would start the motor throught the day but when it came to use my trolling motor just didnt have enough juice to do the job.... I would be limited to a 27 i belive... I found the 750 cranking amp one would probably work for my situation unless others think differently then let me hear it... This is a 14' vhull boat so nothing too crazy.