www.iFourWinns.com

Boat is a 2001 328 Vista. Any idea why? Are the Mando (40 am) alternators not calibrated for AGM's? Sure would be nice to use AGM's as to check the water in the wet cells means taking the batteries out--NOT an easy job due to access (or lack of same) way back on the starboard side.

I'd be interested in the answer to this as well - I have considered replacing mine before next summer.

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2008 Four Winns h180 Bowrider
3.0 Volvo Penta

2013 Dodge Durango HEMI

OK - found an "answer?"

AGM batteries do not provide the high current for cranking that some boats need. CCA does not equal amp-hours and vice versa. The "also" answer is that your charging system needs to be set up for the AGM batteries as they supposedly prefer a "cascade" type charge vs a full blast of energy.

This is just what I've read so far. I know we have had Optima batteries in our rigs and have had issues with them when they are charged or jump-started too frequently (like >5 times and they would not hold > 10v.)

All that said, my sources tell me it is "best for marine applications" to use 2 batteries - a deep cycle and a starting battery. Switch to the starting when starting your boat, both when you are cruising, and the deep cycle when you are sitting still. Supposedly this is "the way to do it" - so take that with a grain of salt.

More info - apparently the alternator produces a constant 14v when running. This constant overcharging weakens the cells, causing them to wear out faster. The solution is an addition to your setup, a module that steps down the charging voltage once the battery is at capacity is needed.

There is also additional information suggesting that the EFI can be harmed (By what I don't know) with the use of AGM batteries.

This is all info from about 8 different sources. I have yet to ask someone who will just give me a straight answer.

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2008 Four Winns h180 Bowrider
3.0 Volvo Penta

2013 Dodge Durango HEMI

I am not sure of the correct answer either but from my reading over the years. I found one of the more pointed reason is the charging voltage. The agm's don't like to be charged at the higher voltage. They can take the higher voltage from the alternator for a short periods but the on board chargers where they are left for long periods will most likely kill them. You would need to change your charger to one that can charge all types of batteries. If you are really interested in going agm I would go to a professional battery shop and see what they can tell you.
I had an old optima that lasted forever and was abused going from one machine to another on a farm. The newer Optimas I hear are not as good since they changed processing plants. I just bought another one last year and haven't abused it as much, so far so good.

If you want to go the best there are a couple lithium battery companies out there. Here is one example, make sure you have a good loan setup before you purchase.
http://www.lithiumion-batteries.com/products/12v-80ah-lithium-ion-battery/

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--2002 3880 Regal Flybridge | Twin Merc 8.1HO **Seven**
--2003 AB 13 VST Console Inflatable | Tohatsu 40hp TLDI **Phish'n ski**
--310 Mercury Inflatable | 1982 9.9 Johnson

Wow. You were not kidding.

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2008 Four Winns h180 Bowrider
3.0 Volvo Penta

2013 Dodge Durango HEMI

I have used AMGs for years. I have even taken them from old boat to new boat. Two of them are now pushing 7 years old with no problems. I have a total of 5, two for each engine & 3 for the house.

My understanding from my chargers manual (ProMarina model - Pro Nautic P) that the charge voltage for AGM is 14.7 were for wet-cells are 14.6V Also, AGM float at 13.8V were wet-cells float at 13.4V. Again, this is out of the manual. So your on-board charger needs to be set correctly!!

I think if you compare size for size that AGMs have more CCA and more A.H. (Amp Hours)

Thanks all. FYI, I have a brand new ProNautic charger, 3 X 40 amps. I have it set to AGM's but charge my two wet cell starting batteries each on their own circuit and charge my two group 31 AGM house batteries, that are in parallel, on the third one. It will not let me select AGM for one bank and wet cell for the other(s).

I figured I'd set it to AGM to treat them as gently and correctly as possible due to their cost. But I'd like to go to them for my starting batteries too, due to not having to check water levels (the starting batteries would have to come out to do so.

For the record, my boat is on a mooring during the week and on weekends we are either on a mooring or the hook--Haven't been on a slip with shore power but twice in 2 seasons now. The generator actually keeps my house batteries pretty well charged just running it an hour or so each morning just for hot water in the shower and the coffee maker, toaster oven and microwave for breakfast or Irish coffee's in the evening!

But if AGM starting batteries will affect my EFI computers, I guess I'll have to live with wet cell start batteries. Think I'll try Volvo tech line too, maybe things have changed since the boat was made?

Now let me see if I have this right? You have 2 wet cells and one AGM battery. The charger is set to AGM. The charge voltage's are different for each type. So you will be overcharging the wet cells then. OK?

If it was my boat, I would just change them to all AGM. Or use 2 battery chargers, one for wet cells and one for AGM.

As mentioned, been using them for 7 years and no problems. Actually, I had the dealer pull them out of my last boat and put them into my new boat. The dealer said nothing to them being AGM other then he will change the battery type on the charger.

Paul I,
Not quite what you say. I have two wet cells for starting, one for starboard motor and one for port motor
Each has a dedicated circuit from my charger as well as being charged by the alternators

My house bank is comprised of 2 group 31 AGM's in parallel, being charged by the third (and a single) output from the ProNautic charger.

So effectively I have two wet cells and two AGM's. but the AGM's are in parallel, so they count as one "bank" and electrically speaking, as one battery.

Yes, I'd be overcharging the wet cells, but I elected that for a few reasons. One, if i over charge them at float mode, then I've ruined only a cheaper wet cell. Plus they are 5 years old even though they tested perfect at the beginning of this year (they were in storage and unused while the boat was out of the water for the prior owner from Sept. 2010 to May 2013). I figure they's need replacing sometime soon anyway. I'd rather not ruin my two NEW $275 each AGM Grp. 31's.

But, I don't want to run AGM start batteries if they will ruin my electronic FI system and FI brain or computers.

I think I'll call Volvo and see what they say
Keep all of you posted!

"Not quite what you say." Forgive me, but it is. Regardless of what bank it is on.

You will not "ruin my electronic FI system and FI brain or computers" But to each there own?

Paul, we're both right methinks--two sides of the same coin in our discussion.

Well, I called Volvo and spoke to a lady in Customer Service / Tech.
She'd been asked the question before and kept the research and answer on file. She gave me two statements--quote;

1) Use of AGM's may affect your ECM's (Electronic Control Modules) (she did not say HOW they would be
"affected")
2) Also use only batteries of 650 cca or larger.

I called ProNautic too--asking them if there was one "compromise" setting they could recommend--they said to call the battery manufacturers and ask them what they recommend as preferred charging rates and voltage ranges and select one profile that will be within bounds for both types.

Third, I called my 4 Winns dealer (3A Marine) in Hingham, MA. for advice. They said they prefer wet cells, but can see why I want AGM's the way I use my boat (lots of deep cycle, never on a slip and poor accessibility). They said they obviously do what Volvo recommends, but cant say they've ever had a problem with a boat where the owner had installed AGM's.

Back to the drawing board! Guess I'll call my battery manufacturers--the AGMs are West Marine which are made by West Penn I believe, don't remember the brand of the wet cells just now.

As before, I'll report back, likely next Monday or so after I check out the wet cell battery brand this weekend.

My last boat was from Jack at 3A. I had a V258 from them. He can tell you if you me6ntion my name. As Volvos goes, I had AGMs in the boat I traded in to Jack and the V258. Also, 2 years in this new boat. Two of them have been in 3 boats and no problems ether with the boat or battery.

Mine are 880CCA group 24s. I can see were ProMarina is going. Can your wetcells take it??

The AGMs I use are normally 229 and on sale at 206 with a 4 year replacment and a 100 month prorated warrenty.

Paul, what brand of AGM's do you use with that warranty and where do you buy them--Rolls maybe where you are in Winthrop?

For the record, I don't know "Jack" but I do talk to Melanie and Pat in their parts and service depts. I use 3-A for most all my parts and pick them up on the way to the Cape with a detour to Hingham off the Southeast Expressway / Rt. 3
My boat was bought new at 3-A back in 2001 and I am the second owner, but I bought it through Smith Yacht Sales who are across the street at the Hingham Marinas office complex who wound up with it rather than 3-A Marine somehow.

Don't know if the wet cells can take it--have to check the battery brand and call them and West or East Penn. Who knows, maybe should be running the charger on a wet cell profile instead of an AGM profile. We'll find out next week.

I recall reading about this when I was comparing starting, dual purpose and deep cycle batteries. Volvo had said not to use either a dual purpose or deep cycle for starting an EFI boat because they have less cold cranking amps than a starting battery, all other things being equal. I think that Volvo is concerned that the voltage would drop too much to run the EFI computer during cranking.
In the same size, AGMs produce somewhat less cranking amps that a flooded starting battery of the same size. I think you could mitigate that by upsizing the battery maybe 2 sizes bigger but then they get REALLY heavy.
I've been using Deka Marine dual purpose gp 27s for years and they are inexpensive and last at least 5 seasons.....

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88 Four Winns 200 Horizon
4.3 OMC Cobra-4bbl
2002 Walker Bay 10/2012 Suzuki 2.5
2008 Walker Bay 8

1998 Jeep Grand Cherokee 4.0/Selectrac
2007 Jeep Grand Cherokee 5.7 Hemi/Quadradrive II

LouC
Interesting thought. I think my starting batteries are grp 27's now but maybe grp. 29's, which is what i was going to replace them with.

Yet on my last Sea Ray with a 7.4L I went to a grp. 31 starting battery, same as my house batteries on that boat and this Vista. Yes it was carbureted though.
Note that Grp 29's and Grp 31's are almost identical in size both phyically and in power, with a slight edge to the 31's which is now more commonly available.

Once I find out more next week, I may take a flyer and go to 2 grp. 31's AGM's for my starting batteries too. That should be plenty for my 5.7L 280hp SXI's. I boat until about Nov. 1st, so it's not like I'm trying to start it when it's zero degrees as if it was a car up here in New England.