New Batteries

[Cincy Aquaholic]

I need to buy new batteries (3) for the first time in 5 years so I'm behind on my research. My set up is one isolated to starboard motor and the other 2 are the combo house batteries and port motor battery. All 3 are the same. I did a quick search but didn't find any recent posts about what brand/size batteries people are going? Any suggestions? FWIW, it looks like the trays could hold a slightly bigger battery than what's in there.

 

[ttmott]

I always buy batteries local; not mail order. I figure if there is a warrantee call the cost of shipping defeats the value of the warrantee.
Regardless, I just replaced all six with X2 Power AGM's from the BatteriesPlus local store. They have a 60 month non-prorated warrantee.....

 

[Cincy Aquaholic]

Thanks. Is there an easy way to know if my onboard charger is compatible with agm batteries? My boat is a 2004 so not sure if the tech has changed. I suppose it would help to pull the manual out.

 

[trflgrl]

Yes, best to consult the manual/manufacturer, but FWIW for quick peace of mind: per the manufacturer, even my oldie but goodie 1989 ProMarine charger/inverter is compatible with both flooded and AGM batteries, just not true gel (AGMs are sometimes mistaken for gel). Their recommendation was to use the same size and chemistry per bank. I went with same chemistry across the board with 3 AGMs, but different sizes/types: a group 34 starting for the port engine and 2 group 31 dual purpose for the starboard/house bank.

If you keep searching the forum, you'll find a lot of threads with battery recommendations.

 

[Zach312]

AGM's are the only way to go in my opinion. Just put 6 AGM's in this spring. I won't miss cleaning up acid out of the battery trays.

 

[FootballFan]

Agm!

 

[gerryb]

My research led to these two, depending on budget: Kirkland signature's house brand or Duracell AGM from Sams Club.

 

[Cincy Aquaholic]

Well, now I'm a little confused. Pulled the literature for my charger out and it shows 2 different model numbers for AGM versus lead batteries. See pic. I guess I need to climb back on the boat and see which one I have.

 

[Woody]

No, it's showing to different chargers for lead acid and gel batteries. You'll be getting lead acid or AGM. AGM is not the same as Gel.

 

[Cincy Aquaholic]

I deleted my last post because I hadn't seen Woody's response and I STAND CORRECTED! Thank you for the clarification. I did a little more research to learn about these types.

So, I guess my last 2 questions are, will the AGM be good for starting batteries as well?

And could I mix 2 AGM's (the one's that power everything and start the starboard motor) with one acid battery that is dedicated to only starting the port motor or should I just bite the bullet and get all 3?

Looking at this one. http://www.samsclub.com/sams/durace...rv-battery-group-size-31dtmagm/prod3590232.ip

 

[paulswagelock]

If you go flooded cell, Sams club has commercial series group 31 batteries for $99 made by Deka. 185 reserve and over 1000 Mca.

These are hard to beat. They are stud type, and slightly larger studs than traditional marine, so you need to open the holes in you battery cables just a bit to fit.

 

[trflgrl]

Well, now I'm a little confused. Pulled the literature for my charger out and it shows 2 different model numbers for AGM versus lead batteries. See pic. I guess I need to climb back on the boat and see which one I have.

No, it's showing to different chargers for lead acid and gel batteries. You'll be getting lead acid or AGM. AGM is not the same as Gel.

Unfortunately, it looks like from their website that the models being offered when my boat was made had different ones for AGM versus acid. I assume since I have acid batteries then that's the charger I have as well. These chargers have been replaced by the 2100 series which now are programmable for either type. I guess I will save some money and just buy the cheaper batteries!

Ditto Woody's comment: it specifies different ones for lead-acid vs. gel. A lot of people mix the terms "AGM" and "gel" but AGM batteries aren't gel batteries.
AGM = absorbed glass mat = an acid battery with different internal structure than one that uses lead plates. Your charger should be fine with AGMs, but if you want to be more confident, contact the manufacturer.

 

[bbwhitejr]

If you go flooded cell, Sams club has commercial series group 31 batteries for $99 made by Deka. 185 reserve and over 1000 Mca.

These are hard to beat. They are stud type, and slightly larger studs than traditional marine, so you need to open the holes in you battery cables just a bit to fit.

+1! I bought 2 of these for house batteries and they are nothing short of great!

Bennett

 

[Mike Blake]

I put 3 AGM blue top in 4 years ago with a new smart charger. No problems so far.