Fortrex 80 battery suggestion

[Sonik]

I'm getting ready to install a Minn Kota Fortex 80 on my Alumacraft Pro 175. It came with an Edge 45 and one group 24 Interstate on the deep cycle side. I suppose I could buy another identical group 24 but I worry that those won't hack it. Or they will but I'll get about 2 hours if that before they go empty. Obviously bigger is better but not being very experienced in these bigger motors I'm not sure it really is needed. I'm not even totally sure a couple group 30s would fit.

I would really appreciate some advice on this before I make an expensive mistake. 

[Puggz]

For a 24 volt system, both your batteries should be identical,. Same model, same age..etc.  You'll need at least a pair of group 27s. group 29s or 31s are better.  I put a pair of Everstart Maxx grp 29s in my boat last year and I've been unable to kill them in 1 days use with a Terrova 80 iPilot.  You get them at walmart but they are mfg by Interstate.  Actually, there are only 3 or 4 battery manufactures. 
These are flooded cell batteries which require a bit of maintenance.  If you fish rough water, make sure you have them secured with a top quality battery tray. Nothing destroys a battery more than it's 70 lbs bouncing around in your boat.  Also, invest in a good quality on-board charger.  They charge faster and treat your batteries better because of the advanced circuitry they use.
One last thing, is be diligent about checking electrolyte levels and use only distilled water to top off.

If you can afford it, go for AGM's.  they are maintenance free but about 3x the price. 

[junyer357]

8 hours ago, Puggz said:

For a 24 volt system, both your batteries should be identical,. Same model, same age..etc.  You'll need at least a pair of group 27s. group 29s or 31s are better.  I put a pair of Everstart Maxx grp 29s in my boat last year and I've been unable to kill them in 1 days use with a Terrova 80 iPilot.  You get them at walmart but they are mfg by Interstate.  Actually, there are only 3 or 4 battery manufactures. 
These are flooded cell batteries which require a bit of maintenance.  If you fish rough water, make sure you have them secured with a top quality battery tray. Nothing destroys a battery more than it's 70 lbs bouncing around in your boat.  Also, invest in a good quality on-board charger.  They charge faster and treat your batteries better because of the advanced circuitry they use.
One last thing, is be diligent about checking electrolyte levels and use only distilled water to top off.

If you can afford it, go for AGM's.  they are maintenance free but about 3x the price. 

X2.  Batteries neex to be identical twins. Same age, brand, size, etc...

I just upgraded from an old 12/24v omc motor to a fortrex 80 like you are looking at and love it.  Between the lift assist and infinite speeds its something we wish we had done sooner.  Battery life during day is better plus we are never between speeds. 

[Sonik]

Well, I did some checking and it looks like group 27 is the biggest I can fit in there. And I lied. There are 2 group 27 sized batteries in there now (cranking and deep cycle). The group 24 was on my jon boat. I don't know where my brain was on that one. Sorry about that. It is a shame I couldn't just grab 1 more Interstate SRM-27 and call it good but the old one is from May 2013.

I'll look into some AGMs. I know Cabelas has theirs on sale for like $170 for the 27 size but I think the quality is a little suspect. Probably fine though. I don't really tournament fish so the smart money is probably on just buying two nice flooded batteries. That Edge is tough on the one group 27. I'm hoping the digital maximizer in the Fortrex helps out quite a bit.

Oh, and the lift assist is the main reason I spent the money on the Fortrex over a Maxxum. I have a real bad lower back so I'm counting on the lift assist and a metal pull cable to provide some relief.

[Puggz]

6 hours ago, Sonik said:

Well, I did some checking and it looks like group 27 is the biggest I can fit in there. And I lied. There are 2 group 27 sized batteries in there now (cranking and deep cycle). The group 24 was on my jon boat. I don't know where my brain was on that one. Sorry about that. It is a shame I couldn't just grab 1 more Interstate SRM-27 and call it good but the old one is from May 2013.

I'll look into some AGMs. I know Cabelas has theirs on sale for like $170 for the 27 size but I think the quality is a little suspect. Probably fine though. I don't really tournament fish so the smart money is probably on just buying two nice flooded batteries. That Edge is tough on the one group 27. I'm hoping the digital maximizer in the Fortrex helps out quite a bit.

Oh, and the lift assist is the main reason I spent the money on the Fortrex over a Maxxum. I have a real bad lower back so I'm counting on the lift assist and a metal pull cable to provide some relief.

You are right, Not all AGMs are created equal...  The best ones are "pure lead" AGMs and usually around $300 each.

[Fishes in trees]

Will the old wiring harness handle the increased load?   What gauge wire is the old wiring harness?  Just a thought.