Battery replacement time

[kmusbach]

We are going to be replacing our 4 4D house battery bank. We currnetly have wet cells and are looking at the Discover EV4DA AGM also considering going with wet cells again huge cost difference. The latest is golf cart batteries. Thoughts and opinions much appreciated.

Takefive

[sailingdog]

I like golfcart batteries and use Trojan T105s for my house bank. However, if you're planning on long-term cruising, AGM batteries might make more sense, due to their higher charge acceptance rate—which results in faster recharge times (at least to the 85% level) and less engine run time if you're using the engine for recharging and have high-output alternators.

If you're just weekending or coastal cruising, then it doesn't matter too much, and going with the golf cart batteries is probably going to be easier and cheaper than AGM batteries. BTW, T105s make a lot more sense IMHO than 4D or 8D batteries, since they're a lot lighter per battery and less likely to cause you to rupture something trying to put them in place.

[camaraderie]

What is your alternator capacity? Do you have separate 3 stage regulator?
Alternative charging source??...i.e. solar/wind/generator. Size of dockside charger and is it a 3 stage charger or older model?
Will you be living on the hook or at the dock or is this a weekends/vacations kind of boat?
Need that info to help you judge the economics of the choices.

[badsanta]

I would check your charging system. If it is set up for a wet cell then go with that. Like the previous poster stated you need a three stage regulator. And a higher charge rate (amp's) For the AGM. But agm don’t need filling, can lay on there side and don’t need a leak proof battery box. But the cost is not only the battery; you may need to include upgrading everything else. Get a good battery book that explains each type of battery and the charging system. You will make a better decision with knowledge

[kmusbach]

Cam,

Our alternator capacity is 100A, yes we have a 3 stage regulator Freedom 2000. Currently our alternative source is a small disel engine that also has a 100A alternator on it. At present we use the boat for weekends and vacations. We are at a dock but are considering moving back onto a hook.

Thanks for the help

[camaraderie]

Kmus...OK...you have a 600amp or so house bank and are capable of charging it at a 15-20% rate no matter what batteries you choose. Setting aside the maintenance issues of flooded vs. AGM...the economics of AGM's only really begin to pay off if you can reduce charging time while on the hook and if you are doing bulk charging several times a week. (i.e. living aboard and cycling). Since you cannot reduce charging time by going to AGM's, your best economic bet is to go with good quality flooded cells like Trojans or similar.

[arenuiwaka]

My T 105's have been good. I would go with AGM if I had the cash. You can get AGM t105s also. The litium ion batteries are quite interesting too.

[johnshasteen]

For the huge difference in cost, I would stay with the flooded batteries. I used to use DieHard marine batteries (I have a four battery bank), and in a pinch I had to replace two of them with the West Marine store-brand dual-purpose batteries - excellent buy - and I've had excellent experience with them. I parked Paloma down in Puerto Isabella for about 13 months, no dock power to run the battery chargers. When we got down to the boat, they started the diesel like I had only been gone a week or two. I'm sold!