Gel or not?

[Shantih]

Being not very electrics savvy and as I'm about to replace 3 x 145Ah 12v batteries I would appreciate comments regarding the merits or otherwise of sealed gel as opposed to open type requiring occasional top up with distilled water.
Thanks

[a64pilot]

Since no-one has answered I'll take a shot and at least maybe that will start some discussion.
All battery technologies have draw backs, shortcomings. From my perspective there is no clear best battery especially if money is a consideration.
I hate to say do a little searching of threads and pick your own. Take into consideration whether you are willing to replace your existing charger(s) too if needed.

[sailorboy1]

The advantage of Gel or AGMs are:
- faster charging acceptance
- don't have to water them

So if your charging system is high output, meaning it has been upgraded, you could reduce the time of running your engine or generator to charge them. This is the main plus unless you just can not stand to check the water once in a while. So unless you are also going to spend money to upgrade your charging system there really is no reason to have the gel/AGM batteries.

[HappyMdRSailor]

Originally Posted by sailorboy1

The advantage of Gel or AGMs are:
- faster charging acceptance
- don't have to water them

So if your charging system is high output, meaning it has been upgraded, you could reduce the time of running your engine or generator to charge them. This is the main plus unless you just can not stand to check the water once in a while. So unless you are also going to spend money to upgrade your charging system there really is no reason to have the gel/AGM batteries.

The major advantage was well pointed out here.... If you were set on gel/AGM, I would personally be steering you towards AGM between the two...

[Cuttyhunk]

Another advantage of AGMs, if you are in a cold weather place and lay your boat up on the hard for the winter, AGMs hold a charge much longer than wet cells. I have 4Ds and they are not coming off the boat until they die. The AGMs hold a good charge (disconnected from everything) all winter.

[Vasco]

Agms are the worst batteries a cruiser could get. If they are not charged right up every time they will die in a couple of years.

[sailorboy1]

Originally Posted by bethflkys

Another advantage of AGMs, if you are in a cold weather place and lay your boat up on the hard for the winter, AGMs hold a charge much longer than wet cells.

I'm not saying that this isn't true or an advantage. But the discharge rate of a fully charged wet cell over the winter is very low and it just doesn't matter except on the AGM sales literature.

[BobnCamie]

We are in the process of purchasing a solar system. I have talked to 5 or 6 different suppliers. The one have have settled on strongly recommends going with 6v. batteries hooked in series. They hold charge much better and re-charge time is quite good as far as holding power. Main problem with wet cell type is that you had better not dis-charge under 50 percent as this cuts battery life quite a bit. This I know from personnel experience. We will be going with wet cell, no big deal, add water every now and then, you will find out how often soon into owning them. Just more boat maintenance.

[ullar]

I would go with good quality gels like Sonnenschein if I could afford them. Smaller self discharge, less maintenance and no trouble when canted over. AGM for starter battery, may be. Saying that I just bought a set of heavy duty deep discharge open lead-acid monoblocks for my boat. Hope they will serve for a long time when properly cared of.

[ranger58sb]

Originally Posted by ullar

I would go with good quality gels like Sonnenschein if I could afford them. Smaller self discharge, less maintenance and no trouble when canted over. AGM for starter battery, may be. Saying that I just bought a set of heavy duty deep discharge open lead-acid monoblocks for my boat. Hope they will serve for a long time when properly cared of.

Just FWIW, usually can't mix gel and LA/AGM chemistry on the same charger, though.

-Chris

[SKG56]

Get, Nigel Calder's, Boatowner's Mechanical and Electrical Manual, this was recommended to me by a friend here on CF, very thorough, very good
Sam

[Terra Nova]

A set of 8D AGM Lifeline batteries were just replaced in a client's boat after ~10 years of service. And they were still performing well.

[a64pilot]

For the money, it's real hard to beat 6V Golf Cart batteries bought at Sams club or similar discount store. Of course there are better batteries, but you pay a whole lot more for very little increased amperage / life in my opinion.

[skipmac]

Originally Posted by Terra Nova

A set of 8D AGM Lifeline batteries were just replaced in a client's boat after ~10 years of service. And they were still performing well.

Would be interesting to know more about the setup. What kind of charging system(s), what kind of daily draw, boat off the grid/on the hook or plugged into shore power for full charging most of the time?

[Lancerbye]

I have two Sonnenschein 8Ds Gel type batteries. these have been used as a house bank only, being charged and discharged through a Heart Freedom 25 inverter using a Link 2000 control system. These batteries have been in use for 14 years and are still going strong. They are only used to provide ac power via the inverter. I also have a solar panel charging system which will charge them while on the hook. My other Batteries are Golf cart batteries that provide 12 vdc to start and instrumentation. Four of these in two series banks. replaced the last set after 7 years.