Golf Cart Batteries vs Marine Batteries

[bobfnbw]

Originally Posted by btrayfors

If you truly wired your six 12-volt group 31 agm's in series, you'd have 72 volts @ 100 AH, not 12 volts @ 600 AH :-)
Bill

Your right of course. Up late last night and working hard on installing a inverter today, put me in a bad mood....

But I will still stay with the agms. Until there is something better out there.... that is affordable.
and that to me is not fla batteries.
bob

[Jmolan]

In the process of designing the load and size battery I am going to need on my simple little 34' Trimaran. This thread has been very helpful. I ran across this site. Pretty much a ton of info.

Comparing marine batteries (Gel, Absorbed Glass Mat (AGM), flooded lead acid)

[cal40john]

Originally Posted by Albro359

When batteries like AGMs are available I cannot understand why anyone would want flooded cell batteries in their boat...I have 4 x 12V 105 Ah AGMS , 1 for start and three in parallel for house power...a 110A Balmar on my little Yanmar with one 1/2" belt, a NEXT STEP NS2 reg and no problems
Btw I run an autopilot, radar, laptop, chartplotter, SSB, VHF, a 35 l/hr watermaker and all the usual lights ... engine driven fridge though....and no problems...no fumes, no acid, no topping up, no hydrometer, no bother !

Cheers
Alan

I want AGMs, I want a $600,000 Cat, I want a lot of things. I have a 1965 Cal 40, I have a budget, I have batteries that cost less than half per amp-hr as you do that will probably last as long or close to as your AGMs.

And if I want to go cruising, I have to stick to a budget. I hope I have increased your understanding.

John

[billyehh]

I am also looking at new batteries. I have 10 year old AGM's that have finally died. They are 225 amp 6 volt and have the same profile as the Trojan 105. After researching and doing a fair amount of calculating, I have decided to repower with Lifeline AGM 225 amp 6 volt batteries, basicaly the same as the originals.

Why do this when they are more than $100.00 more than the Trojans.--- very good reasons.
1. My battery bank is in the saloon underneath a bench seat. For safety reasons I want a sealed battery that will not leak.
2. I have 2 130 amp alternators and the AGM's will accept this large amount of current as long as the voltage remains below 14.4 volts. Trojans will only accept 120 to 150 amps. This cuts down on engine hours.
3. The space is dificult to reach, so maintenance free is a plus.
4. The batteries are close to the inverter/charger so limited hydrogen venting is a plus. It is vented with anexhaust fan for the refrigeration.
5. They last longer given that both systems are cared for. This is important for shipping to the carribean.

Given that they last longer then Trojans, the per year cost is similar after you get over the initial upfront cost.

It is important to have 3 stage regulators and chargers since AGM's are very sensitive to overvoltage. If not go with Trojans, they will take it better, but they will also last longer, with proper regulation.

[Albro359]

Dear John (Cal40)....well you've got 10 yrs on me...my boat was built in 1974, but I've spent a lot of time and enrgy upgrading everything over the last few years to try to make it bullet proof for extended cruising.

I had flooded batteries and they were a pain .. the extra cost of the AGMs has relieved me of that pain...and I sail much happier !!

All the best

See you out there !~

Alan

[sageofsalem]

They even work "upside down." (for you catamaran owners) Two years ago when I bought my 8D Gels, glass mats and gels were hard to find and expensive. I gave 399 apiece, (with the 8D glass mat going for over six) for mine as I was going offshore and had doubts about getting them where I was going to be.


I've around two thousand AH and run the Heart and a smart charger. I would like to shake the hand of Whoever set up my boats electrical system as it is a sweet-running system, especially with the excess house capacity..Now I just have to install a dedicated engine battery to get right.

I weigh over 250 and putting those batteries out and under my tool bench took alot of my strength and would be a chore for a smaller guy or gal, but that's what was in the boat when I bought it from Quen Cultra, Bless the man.

[Jmolan]

Originally Posted by billyehh

I am also looking at new batteries. I have 10 year old AGM's that have finally died. They are 225 amp 6 volt and have the same profile as the Trojan 105. After researching and doing a fair amount of calculating, I have decided to repower with Lifeline AGM 225 amp 6 volt batteries, basicaly the same as the originals.

Why do this when they are more than $100.00 more than the Trojans.--- very good reasons.
1. My battery bank is in the saloon underneath a bench seat. For safety reasons I want a sealed battery that will not leak.
2. I have 2 130 amp alternators and the AGM's will accept this large amount of current as long as the voltage remains below 14.4 volts. Trojans will only accept 120 to 150 amps. This cuts down on engine hours.
3. The space is dificult to reach, so maintenance free is a plus.
4. The batteries are close to the inverter/charger so limited hydrogen venting is a plus. It is vented with anexhaust fan for the refrigeration.
5. They last longer given that both systems are cared for. This is important for shipping to the carribean.

Given that they last longer then Trojans, the per year cost is similar after you get over the initial upfront cost.

It is important to have 3 stage regulators and chargers since AGM's are very sensitive to overvoltage. If not go with Trojans, they will take it better, but they will also last longer, with proper regulation.

Thanks for that most excellent description. I appreciate the time taken on this forum to post the battery and charging set up folks have.

[bobfnbw]

Originally Posted by billyehh

I am also looking at new batteries. I have 10 year old AGM's that have finally died. They are 225 amp 6 volt and have the same profile as the Trojan 105. After researching and doing a fair amount of calculating, I have decided to repower with Lifeline AGM 225 amp 6 volt batteries, basicaly the same as the originals.

Why do this when they are more than $100.00 more than the Trojans.--- very good reasons.
1. My battery bank is in the saloon underneath a bench seat. For safety reasons I want a sealed battery that will not leak.
2. I have 2 130 amp alternators and the AGM's will accept this large amount of current as long as the voltage remains below 14.4 volts. Trojans will only accept 120 to 150 amps. This cuts down on engine hours.
3. The space is dificult to reach, so maintenance free is a plus.
4. The batteries are close to the inverter/charger so limited hydrogen venting is a plus. It is vented with anexhaust fan for the refrigeration.
5. They last longer given that both systems are cared for. This is important for shipping to the carribean.

Given that they last longer then Trojans, the per year cost is similar after you get over the initial upfront cost.

It is important to have 3 stage regulators and chargers since AGM's are very sensitive to overvoltage. If not go with Trojans, they will take it better, but they will also last longer, with proper regulation.

I want AGMs, I want a $600,000 Cat, I want a lot of things. I have a 1965 Cal 40, I have a budget, I have batteries that cost less than half per amp-hr as you do that will probably last as long or close to as your AGMs.

And if I want to go cruising, I have to stick to a budget. I hope I have increased your understanding.

John

John your point is valid, and if money was the only object, then flooded lead acid golf cart batteries would be the most logical choice. For many they are.
Having had them, and then having a boat sink under me, and those batteries leak acid all over the boat, and of course be useless then, and they vented, had to have regular maintenance, had to check them with a hydrometer, and then figure out a good way not to drip acid on my boat and me... and making sure they didn't vent inside the boat.. oh and of course the PO put them on top of each other in a seriously piss poor install, and of course they vented inside the boat while charging... and exposed to possible explosive gas to the engine compartment... But then all that is ok, I guess except for the fact that FLA batteries will not accept a fast charge. And I want to minimize charging times...
So AGM's are the way to go IMHO. Maybe not yours. Or maybe you think you would like them, but just can't afford them. Its fine. But there is a lot of ways to calculate being able to afford something. Like, Lowest cost now, or lowest cost over the time I will have them. Do I spend more now, to get more in the long run, and that does't mean longer cycles but better satisfaction.... Only each one of us can decide this. Its like the anchor thread, or power over sail, or any number of things that boaters differ on.
I had a local marine repair guy give me a hard time on batteries.
"I can't understand why you sailboaters want so many damn batteries" he said. Of course he didn't. He had a chris craft power boat with 2 big diesels and a genset. To him, all he needed was a good start battery.

Billyehh gave a good description above. Read it and then choose the next time you need to replace your batteries, think carefully about both the good and the bad of both agm, and FLA batteries. Maybe by then it will be a moot point because we all will be buying cheap made in the usofa lithium batteries.... hey a man can dream, can't he?

Bob

[gettinthere]

My reading over the years has always shown wet cells last longer than agm's. Almost twice as long. I've never, before this thread, read of agms lasting 10 years.

[Maine Sail]

Originally Posted by gettinthere

My reading over the years has always shown wet cells last longer than agm's. Almost twice as long. I've never, before this thread, read of agms lasting 10 years.

My own personal experience with AGM's, and having a friend who is a battery distributor who sells AGM's, agrees with your position that AGM's do not always outlast wet cells. I have yet to see any empirical evidence by an independent testing facility that shows that AGM's will consistently out last wet cells. If anyone knows of such a white paper, that was NOT funded by a battery manufacturer, please send me the link.

My neighbors 6 Lifeline AGM's were dead at the beginning of last season, it would have been season six. He babied them and has a top notch charging system. In fact the system he charged the AGM's with is a much better system than the one he used for charging his T105's. He got 8 years out of T105's with a dumb regulator. At 8 years his T105's were still going but he just wanted AGM's for the faster acceptance.

I like AGM's, and LOVE the high acceptance, but have been talked out of them every time I talk to my buddy Dave and see a pallet full of AGM's in the 4-6 year old range deader than a door nail and ready for recycling.

AGM's have many benefits but longevity is not one I have had the pleasure of witnessing and I see LOTS of dead AGM's at Dave's shop, and I do look at the date codes. I've yet to see any past the 6 year mark but that means perhaps some are out there still going..? Ten years would be nice!!

[Not Sure]

AGM's will last 10 years....if they spend 7 of those years in a garage on a trickle charger.

[Momo]

My two-cents worth. After watching friends on another boat drive their Trojans into the dust every day and resurrect them at night (they were rebuilding their boat while at anchor), we bought eight Trojan T-105s (6 volts). That was almost six years ago and they are still going strong. We live on our boat, and never use shore power. I wouldn't worry about estimating amps hours, etc. Just make your battery bank as big as possible--the larger the bank, the more efficient the charging, and the greater the longevity of the batteries. And make sure to equalize them every so often. If space is a priority, use it all for one battery bank. Two battery banks (i.e. a second bank of starting batteries) are a waste of money & space and create complications and expenses you don't need. The modicum of 'safety' one from two banks is marginal or even delusional. The only time we've had to sail without the motor is when our starter broke. A second bank of batteries would have done nothing for us. Luckily, since our primary source of charging is Honda generator, the lack of an engine did not pose difficulties as far as our electrical power was concerned.

Regards.

[billyehh]

AGM's are not for everyone. As I noted in my previous post there are very sensitive to over voltage. This will destroy them quickly. Also, if you discharge them deeply down to less then 40% of capacity they will have less cycles then a Trojan. If possible only use the top 20% and you will get almost double the cycles of wet cells.

I also use my boat on the hook. I did not use my shore pwoer charger at all last year using solar and engine. I reeally like having the fast acceptance and also fast discharge rate when I use my 1500 watt inverter. Another plus that I did not metion before is the low internal discharge rate. I can leave the boat for the summer and only lose about 5% rather than the 25% discharge of a wet cell.

Most long term crusers here in the Eastern Caribbean use wet cells, the majority being Trojan 105's. If I had a good wellventalated space for my batteries and spent all my time on the boat and had a generator for charging I would probably get Trojans as well. Most of the other boats with AGM's get good long life from them, at least as long as the average wet cell.

Every different battery type is a compromise and the user has to calculate what is the best for his situation. As one poster said hopefully we can use lithium batteries the next time we have to repower.

[DotDun]

I had (3) 4D AGMs go dead at 30 months old. Replaced with (2) 8D flooded which are still going strong at 4.5 years.

At the time, (3) 4D AGMs = $1200, (2) 8D flooded were $400.

[Intentional Drifter]

I have a 600 amphr bank of Sonnenschein gel cells that after 7 years are still OK and I'm certainly hoping to get another year out of them (knock on wood!). However, it is only a matter of time, as we all know. For many of the same reasons given by Billyehh, I would not replace with flooded.

I'm very interested in the Odyssey, which is making the Sears DieHard Marine Platinum PM-1 (100 amphr) @ $250/ea. and is a re-badged Odyssey 2100.

To replace the gels with an equivalent set of Mastervolt AGM, would run $2K @ Fisheries Supply; $1800 for West Marine's AGM.

The Odyssey/Sears would run $1500 and (if Calder is correct), give me 50% more daily usable amp/hrs with the same number of life cycles, while reducing charging time by about 50%, too. (I have a Victron Multi inverter charger that can provide 120 amps charge current.) If you can wait for one of the "Friends and Family" sales at Sears, you can save 10% off of that.

ID