Batteries? Deep Cycle, AGM, Electric Vehicle?

[kopp210]

Went to my local battery shop yesterday, hoping to get some guidance on adding batteries to G23. Came away with more questions than answers. I am looking to add ~400 Ah in an additional bank for the stereo and lighting. We discussed the differences with Wet Cell, AGM, and electric vehicle batteries but couldn't really pick one over the other.

Ideally I would keep the house bank combined with the starting battery (2 Deka Wet Group 27) most of the day when riding around, then run the stereo bank down jammin in the afternoon, and replenish with a good onboard charger back at the dock.

From your guys experience what is a good battery for this set-up? Is there a solid valuable reason to go AGM? Is there issues with using 4D or 8D Electric vehicle batteries?

[nyryan2001]

There isnt a definitive answer on this, you'll get a lot of answers.

The absolute undisputed best ah bang for the buck is 2 or 4 6V golf cart batteries wired in series. You may not have room for that.

The regular "Ford F150" standard wet cell approach would be Interstate SRM 29s or for a little more Dekka 29s. Talking cost per ah here, keeping in mind a great warranty.

You may need to do AGM to be able to mount them on their sides for fitment. I doubt you will get any solid consistent feedback that AGMs really outperform wetcells for all the money.

Suggest you approach this from another angle.... ask folks who have large additional battery banks, how they did it and why? Also, absolutely criticial which you did not ask about, is how they fused and ran the wiring to keep it safe and above/within ABYC standards.

[kopp210]

Yes any system pics would be appreciated. I am going to rely on the local shop to get the install to spec. But any really slick installations would give good ideas to steal.

The shop actually recommended an exide deep cycle "cause it was the cheapest". Not sure I'm looking to pick anything to put in a g23 cause it's the cheapest, but not looking to light money on fire either.



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[nyryan2001]

where does he plan to mount them and how many? What type of mounts or boxes will they be in?

The slickest cleanest battery install I've seen is from Scream Marine. They crammed 6 group 24 Stinger AGMs down in the original 2 battery location on Nauty 220s last G23, not sure what he has in his newer G. I wanna say that was $1500 range.

[MLA]

For the money, 2 pairs of 6V GC's, providing you have a space to locate them and the battery boxes. This option is going to require more height than width/length as compared to other options. Next best option would be 3 or 4 AGM to get you at or over your 400Ah target. Typically not too tall, but will require a lot of floor space. I think these will handle the deeper, more frequent cycles better then traditional wet cell batteries for your application.

[Tryathlete]

What about a battery from a wrecked Prius or Camry? I don't know what they go for at salvage pricing, and I suspect they are 48v or something like that in need of a step-down to 12V.

[core-rider]

Like already mentioned your best bang-for-buck is going to be Interstate deep cycles or Deka. I wouldn't waste the extra money on AGM unless the mounting requires them. I know you said you're using an installer and expect them to keep everything to spec, but most car audio shops I've seen don't know squat about marine. I don't know who you're using, but hopefully they know their stuff and can make it safe... Most don't.

[nauty220]

Come on Ryan they weren't crammed lol! I just put pics up in the Lets See It sticky so you can see the battery configuration

[xrichard]

AGM has almost no benefit unless you need to mount them on their side. In fact, generally, you'll find less storage for a given size compared to wet cell. Besides the ability to put them on their side, the only benefit is they tend to resist damage from vibration better than standard wet cells--though probably not as well as golf cart batteries.

The best is banks of 2x 6v golf cart batteries. They are designed for deep discharges and are very resistant to vibration damage. I've never used them on my boat, but I use them on my RV and the difference is unbelievable--they last longer and I can abuse them with deep discharges and they still recharge and hold the charge.

I've mentioned here before that I always put in a Blue Sea ACR to automatically combine the batteries for charging while running and isolate starting from stereo while sitting in a cove. Wiring to get around the issue of a two bank charger back at the dock is super easy....there are two quick ways to do it. You can also switch manually with a 1 / 2 / Both switch from Perko or Blue Sea, but having it done automatically is nice. And it's an inexpensive solution: $150-175 in parts and a 2-3 hours for a clean install.

[swankster]

Come on Ryan they weren't crammed lol! I just put pics up in the Lets See It sticky so you can see the battery configuration

I heard your 2013 G23...I think you could ride either wave, the water or the sound.