AGM battery plus Intelli Power PD2030 converter

Todd320

Todd320

Well-Known Member
Jul 21, 2016
1,508
St. Petersburg, FL
Boat Info
2007 Sea Ray 320DA
Engines
Twin V-drive 5.7L 350 Horizon
i have 4 deep cycle SRM27 interstate batteries, 600 cca. The batteries are almost 3 years old. Earlier in the year, they never had an issue starting my boat or keeping the fridges and radio going all day.
Assume they are dead now for this
Conversation.
I am looking to get AGM Batteries, found some deep cycle Duracell for $154 through Sam’s club. 800cca, 31DTM-AGM.
First question, surely these would be just as good, if not way better at starting the engines and running the electronics and fridges for the day. Right?
Second question, will my battery charger work just fine with these AGM batteries? Getting mixed information on internet regarding AGM and battery chargers.
 
A group 31 is a little larger, so yes, more CCA and Ah would be expected. Thats always a good thing to have more of.

I do not know that charger, but answer this to yourself. Can you select the battery type for example wet cell or AGM?

Is it large enough to handle bank of batteries that could sum about 300-400 Ah? Ideally you would want a 30 to 40 amp charger thats enough banks to service each bank individually.
 
I had a 320DA with those batteries and that charger. The batteries lasted over 7 years.
My current boat has a PD2040 converter using the same batteries 5 years and still going strong.
 
I never had a problem on either of my last two boats with AGMs and the original chargers...

Now Gel batteries (which are not AGMs) are a different story.

A lot of my dockmates have bought those Duracell 31 AGMs from Sam's and have had great experience with them...
 
carterchapman said:
I never had a problem on either of my last two boats with AGMs and the original chargers...

Now Gel batteries (which are not AGMs) are a different story.

A lot of my dockmates have bought those Duracell 31 AGMs from Sam's and have had great experience with them...
Click to expand...

Carter, do you remember what make and model charger you had on your 410, and which AGM’s did you use that fit in the trays for both motors and the genny (5 in total)?
Both Interstate group 27 batteries on one of my motors were new this past May, but the two on the other motor and the one for the genny are marked as installed in 2011 so they are due to be replaced this year as PM.
As long as I’m buying 3, I’ve been thinking of replacing all 5 with new AGM’s and if I could keep the original charger it might be a deciding factor. If I can fit group 31’s in the present trays it would probably seal the deal.
 
JVM225 said:
Carter, do you remember what make and model charger you had on your 410, and which AGM’s did you use that fit in the trays for both motors and the genny (5 in total)?
Both Interstate group 27 batteries on one of my motors were new this past May, but the two on the other motor and the one for the genny are marked as installed in 2011 so they are due to be replaced this year as PM.
As long as I’m buying 3, I’ve been thinking of replacing all 5 with new AGM’s and if I could keep the original charger it might be a deciding factor. If I can fit group 31’s in the present trays it would probably seal the deal.
Click to expand...

i used Sears Diehard Platinum AGMs (4 Grp 31's) on my 340 with the factory charger in 2010 - they are still going strong for the current owner - however, Sears doesn't carry them any more. The late Dominic (OSD9) put Optima Blue Top (5) Grp 31's in my former 410. They are still going strong with the factory charger. I won't be back to our Chattanooga dock until May to see what the charger model is, and the current owner and his wife are both having surgeries in Dec, so I won't even be able to ask until Jan or Feb. The Grp 31 Optima Blue Tops fit in the trays perfectly. A lot of dock mates were buying the Duracell AGM Grp 31's from Sam's for about $50-$100 less than the Optimas...
 
I really need to write a long post about batteries and see if we can make it a sticky...

Here are some "truths"

1. AGM's are not as good as wet cells... unless you can't or don't want to water the batteries. The only benefit they have is they need no maintenance if properly charged.
2. AGM's do require a specific charge profile to properly charge them. They can typically be charged faster then a wet cell.
3. Gel Cells are a completely different animal, very good, but costly
4. Optima's always come up on any forum... fact is they are spiral cell and are not really very good for anything marine compared to other AGM's/wet cells.
5. Li-Ion or Polymer are coming... slowly, as you have probably read they can be dangerous if they short-circuit. They really are amazing both in weight, performance, and charging.

Judging/comparing battery truths...

1. Heavier is a good indicator of quality, fancy colors or marketing is a joke, look at the weights of comparable batteries.
2. Sometimes it is beneficial to wire multiple batteries together to "form" your bank... if a cell goes bad you can replace just that cell and you typically gain capacity... but at the expense of weight.

Hopefully this helps somewhat, let me know if you need more explanation or if I missed something.

Josh
 
Josh - do you not find AGMs last twice as long as wet cells?

That has been my experience along with all other AGM owners that I know.
 
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I have 4 Deka Marine Master group 31 batteries. 2 of them just finished their 7th summer with no problems. I will replace them in the spring just because of their age. The charger is the OEM old school and I have no reason to replace it until necessary. Check the water levels 2-3 times a year and they take very little water. I would go with AGM if it were difficult to access them for maintenance.
 
This is really helpful, thanks everyone. Given the price, I am going to purchase these in the next few weeks. I will let you know how it goes. I want AGMs for two reasons, they last longer (or should), have a better shelf life (my boat sits without a charge for 2-3 weeks at a time), and 0 maintenance (not that hard to add Water to batteries, but it is a pain, visibility is poor in my battery compartment, and the heat is stifling, and my hands shake, so pouring anything slowly never works out well for me!)
My charger’s normal mode is 13.6v, and based upon my research so far, this fits into the charging profile for these AGM batteries.
 
Carter

The reason many people perceive the AGM batteries to last longer is because they don’t properly maintain or charge the wet cells and typically boaters are using cheap wet cells. Agm’s are not bad by any means but they have less charge cycles compared to a wet cell. Now we could turn this into the best oil thread but some other common issues are the chargers... marine chargers, heck all battery chargers, have gotten so much better over the years it is incredible. They have specific charge profiles to charge different types. They go through absorption, condition, maintain, and sometimes equalization. So I think lots of people at some point replace their old charger then the batteries and assume it must be the these great agm batteries.

Agms and gel have their place, if you can’t easily get to them for watering or flat out know yourself and you won’t do it then you should buy agm’s. Or if you need to install them on their side. They are a little more vibration resistant so you will see folks like NASCAR use them. Not to dive in too deep but here is the “issue” with using AGM’s. They accept a charge rate of 2.4v/cell just like wet cells but... once they go into conditioning mode they only way 2.25v/cell. This is why it is imperative you have a proper charger with AGM setting if you want to get the life out of your AGM’s.

Just a side note, I Have Rolls Surrette batteries in my boat, they have a 7 year warranty and many of the boats around here have had them for 20 years. They are designed to be used by boats and I don’t like changing 175lb batteries so I installed these. Water them once every 6-8 weeks and all is well.
 
Thanks for the great info Carter. I’m very encouraged by your experience with the Optimas in your 410.
The batteries in this boat, while not impossible to get to, aren’t in the most convenient place to keep checking and topping off. That’s one reason I want to consider AGM’s.
We usually spend a full day on the hook every weekend during the summer. With two fridges and a stereo going during those days on the hook, battery power is always a concern for me. I’d like to increase available capacity, so that’s why I am looking to go to group 31’s.
Many people I know rarely spend time on the hook, are usually plugged in to the dock when not running, and capacity probably isn’t as much of a concern for them.
I love having the genny, and we try to use it a couple of hours every week, but I’d rather run it more while we are cruising because while it’s relatively clean and quiet, we are often rafted up when on the hook and the boat on my starboard side doesn’t always appreciate my genny running.
There are no Sam’s Clubs anywhere near me so I have to consider brands other than the Duracells. I’ve seen the Optimas go on sale a couple of times a year at places like Auto Zone so right now they are at the top of my list.
A couple of decades ago I used to swear by the quality of many things from Sears. I had a Craftsman grill that lasted over 20 years, and my Craftsman Snow Blower is now 22 years old. My next Craftsman Grill was junk after 2 years (replaced it with a Weber), and many of the other items they sell are now more KMart quality so I’d be reluctant to buy batteries from them.
At this point, I guess the next thing to do is call Pro Mariner and ask them about using the existing charger with AGM’s.
 
I've heard from some that Optima quality took a dip for a while, but I did not experience any problems. Being in the South, we run the generator almost constantly due to the heat and humidity, so we probably never did deep discharge cycles on either of the last two boats with AGMs. I guess my experience with wet cell longevity vs, AGMs is different from Josh, but I always had AGMs last a minimum of twice as long and that was with the original charger in both previous boats. The location of the 5 batteries in my 410 enabled me to put two plastic tool boxes on top of the batteries since I didn't have to check them.

Josh - I don't think my dock hand could manage the weight of the Rolls Surretes!!! Regular 8D's were heavy enough in my current boat for him!!
 
Carter

There are just so many variables to quantify it becomes a mess. I'm willing to bet the AGM's you purchased were of much improved quality then the wet cells you had previously purchased. It also depends on use, depth of discharge, and charging profiles. I would recommend a charger with the correct profile matched to the batteries you have. This profile information is provided by all reputable manufactures. Lastly, don't forget there are different types of each style, deep cycle, combo, starting....

See the rabbit hole we are going down? :) I say do what is right for you, but do match the capacity, charger, and batteries to your use. Some AGM's can regularly accept a DOD of 80% where some Wet Cell Lead Acid prefer 50%. No big deal but something to think about. What you should be comparing for house batteries is the Reserve capacity from one brand to the other.

As far as the comments about Optima... These batteries are spiral would so they are not as susceptible to vibration. Other then that, I think you can find much better AGM batteries for the money. It irks me they also can require a different hold down as well, but they are good marketers so I guess they sell batteries. I don't dislike them, just know that you can buy better bateries for less money.

When all is said and done, AGM's work the exact same way as a wet cell. They are sealed "wet cells" with glass mat's instead of lead plates. They can discharge a little deeper but have less cycles then the wet cells and cost significantly more. To each his own, I knew this would end up being a "story!"

Josh
 
You would be better off dedicating the engine starting batteries and having a dedicated house. That way you dont have worry about starting your engines with dead house batteries
 
carterchapman said:
I've heard from some that Optima quality took a dip for a while, but I did not experience any problems. Being in the South, we run the generator almost constantly due to the heat and humidity, so we probably never did deep discharge cycles on either of the last two boats with AGMs. I guess my experience with wet cell longevity vs, AGMs is different from Josh, but I always had AGMs last a minimum of twice as long and that was with the original charger in both previous boats. The location of the 5 batteries in my 410 enabled me to put two plastic tool boxes on top of the batteries since I didn't have to check them.

Josh - I don't think my dock hand could manage the weight of the Rolls Surretes!!! Regular 8D's were heavy enough in my current boat for him!!
Click to expand...

I like the idea of being able to store something in the space above the batteries too. Storage space is kind of limited in the bilge of my 410 and I can always use more of it.
 
Josh,
Any AGM recommendations for a nationally available brand other than the Group 31 Optima Blue Tops in that price range? We don’t have any Sam’s Clubs around here.
If Pro Mariner green lights my existing charger fo use with AGM’s I’m going to go that way so I don’t have to contort to check and fill wet cell batteries and may be able to get some spare parts bin storage above them.
 
Walmart has Group 31 marine batteries from VMAX, I am not familiar with the brand, but maybe a starting point for research.
 
JVM225 said:
Josh,
Any AGM recommendations for a nationally available brand other than the Group 31 Optima Blue Tops in that price range? We don’t have any Sam’s Clubs around here.
If Pro Mariner green lights my existing charger fo use with AGM’s I’m going to go that way so I don’t have to contort to check and fill wet cell batteries and may be able to get some spare parts bin storage above them.
Click to expand...

Check with your local Interstate dealer, they have marine AGM's in Group 31 size that fit in the group 27 trays in my 340DA.
https://www.interstatebatteries.com/recreation-vehicles/marine-batteries/dual-purpose
 
Rolls surrette. Mastervolt. Northstar. Trojan. Deka. Lifeline.

Those are the top quality brands.

I would say the name brands you are familiar with are mid grade batteries. Bosch, diehard, interstate...etc

Then there are the House brands. Some are ok and some are not. They are all rebranded so you have no idea what you are getting. Walmart, autozone... all have house brands but one year they could be sourcing from interstate and another year China.
 
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