Battery -- glass mat, gel, or acid

Roger Long · Jan 12, 2009

mikenovit said:
QUESTION: Can you use a glass mat or Gel battery on the boat without concerns?

That's two different questions. Gel cells require special charging regimes and you probably don't want to go there. AGM's can be treated just like wet cells, are much safer, and give better performance. Their only drawback is cost.

I seem to be in a distinct minority in believing that the extra cost of the AGM's is justified and in not wanting to ever have wet cells with their free acid on my boat.

The real answer is that you can't use any battery on a boat without concerns but AGM's reduce them to a minimum. For that matter, you can't have a boat without a lot of concerns

Ross · Jan 12, 2009

I have had AGM batteries for ten years. They are charged with the alternator only. Hold their charge all winter, and start the engine each spring without a problem. In their life I see them twice, once when I install them and once when I replace them. That has happened once.

sailingdog · Jan 12, 2009

Of the three chemistry types typically found in marine deep cycle batteries, Gels are probably the worst, since they seem to be the most vulnerable to damage and have the worst features of both wet-cell and AGM IMHO.

If you're going to be able to keep the batteries topped off regularly, AGM or Optima batteries may be a better choice than wet cell, especially if you're the type of person to forget about checking electrolyte levels.

If you're going to do the proper maintenance that wet-cell batteries need, like periodic equalization, checking the electrolyte levels, etc, then they're probably the way to go, since they're far less expensive and can be used to a greater number of charge/discharge cycles.

That said, most batteries don't die a natural death but are killed through neglect or abuse.

Don S/V ILLusion · Jan 12, 2009

mikenovit said:
I recently decided to replace my starter battery on my Oday 322. I looked at various web sites and decided to buy a battery from Sears. The woman working there said the marine battery she was selling for $200 would work on my boat charger or my shore power charger. I bought it, then heard from other websites that the battery I bought (Marine Platinum) could not be installed with ship battery charger but needed a MAINTAINER. So I took it back, went to Walmart and bought a marine battery $82.

QUESTION: Can you use a glass mat or Gel battery on the boat without concerns?

Never heard of a "maintainer" (is this a trickle charger?) and there is really no such thing as a "marine battery". Some marketing departments guess, apparently correctly, that they may charge more money if they label a battery as such. There are deep cycle batteries and start batteries and they also sell combination batteries but for what you want, all you need is a decent car battery.

Steve Dion · Jan 12, 2009

There is nothing wrong with Gel batteries (assuming you have a proper charging system). I got over 10 years from my WM Gels.

My current configuration includes an Optima for my "backup starting battery" and Gel's for my house keeping. I also installed a Xantrex XC charger that can handle multiple battery chemistries.

Gels should see comparable life or better than AGM but will not charge quite as fast. They need no maintenance (including cleaning battery terminals) and should outlast most of the flooded battery types.

If you are not a regular maintenance type, then either the Gel or AGM batteries are the ticket. If you prefer to spend you time doing maintenance and wish to keep maintenance ahead of sailing time, then you will probably save money with a flooded battery bank.

sailingdog · Jan 13, 2009

The maintenance on wet-cells is fairly minimal provided you have the proper charging setup and aren't boiling off the electrolyte constantly. I check mine once a month and generally only have to add water once or twice a season.

Steve Dion said:
There is nothing wrong with Gel batteries (assuming you have a proper charging system). I got over 10 years from my WM Gels.

My current configuration includes an Optima for my "backup starting battery" and Gel's for my house keeping. I also installed a Xantrex XC charger that can handle multiple battery chemistries.

Gels should see comparable life or better than AGM but will not charge quite as fast. They need no maintenance (including cleaning battery terminals) and should outlast most of the flooded battery types.

If you are not a regular maintenance type, then either the Gel or AGM batteries are the ticket. If you prefer to spend you time doing maintenance and wish to keep maintenance ahead of sailing time, then you will probably save money with a flooded battery bank.

kloudie1 · Jan 13, 2009

Battery, Glass Mat, Gel..Wet cell

I am with Roger.. The AGM's are nice if ya have the budget.. I am conservative and use Sam's wet cell, deep cycle Batts.. BUT they are doing fine thanks to my Xantrex and the remote watering kit.. (http://www.basspro.com/webapp/wcs/stores/servlet/Product_10151_-1_10001_52557____SearchResults) Takes about 3minutes to water up the batts .... On an old Hunter 34, that used to be an hour job that involves wiggling down into the aft stbd "pit" ..
Starting batt only .. ya can use a regular low/no maint automobile starting batt, since they are inexpensive and the service on a boat is excellent considering that they are designed to live under a car hood at very high "soak" temps and start the car at very low ambient temps.. Standard charger/engine alternator works fine for those.

Roger Long · Jan 13, 2009

kloudie1 said:
The AGM's are nice if ya have the budget

The amoritized price difference between wet cells and AGM's doesn't even show up as a blip in the budget for even a funky, low budget, 32 footer like mine.