House Batteries

JoAna

Member
Feb 10, 2018
135
San Diego, CA
Boat Info
2005 420DB
Engines
Cummins 6CTA 8.3 450HP
i'm not sure if I'm going out of place or if this is the right way to post a new question. (if not, please advise) but:

Hello All. We have 2005 42 Sedan Bridge that presently has group 24 house batteries and i'm very suspicious (should they be group 27)???
 
Doesn’t sound right. My boat for instance has 4 group 31 batteries. Figure yours should have at least that. Regardless your manual should list the recommended batteries for your boat.
 
I agree with the above. My '99 340 had group 27's (three of them) and I would be shocked if a 40'+ wasn't at least that big.

I guess the bigger question is whether or not they are working for you? There are lots of battery threads around here. Generally the bigger size is most impactful if you spend a fair amount of time on the hook. I don't know the capacity difference between the 24 and 27 but I could go 2 full days with two fridges running and occasional toilet, water, radio, etc on 2 group 27 house batteries with no problem. I didn't see the need to go any bigger than 27's based on this experience. Your mileage may vary.
 
This is one of those cases where bigger is definitely better. Put the biggest batteries in that will fit. Most boats with 450hp diesels would have 8D batteries.
 
Just this past year I was in need of 3 new batteries and went from group 27 to 31. Could not find any 27's locally and went with 31's. I really think group 31 took their place on the market since they are pretty close if not the same size.
 
Just this past year I was in need of 3 new batteries and went from group 27 to 31. Could not find any 27's locally and went with 31's. I really think group 31 took their place on the market since they are pretty close if not the same size.

One thought on this (very installation specific) is to take a look at your terminal location compared to available cable length before making a switch in battery size. My 340 had EXACTLY the right amount of cable for 27's nestled side by side on the bilge floor between the engines. They were accessible only with substantial amounts of swearing, sweating and rib-puncturing maneuvers over the tops of the engines. If I recall correctly the terminal location would have been slightly different on the 31's..(???) I would have thrown myself overboard had I removed the 27's from my bilge floor and found the 31's would not work because of lack of cable length :)
 
i'm not sure if I'm going out of place or if this is the right way to post a new question. (if not, please advise) but:

Hello All. We have 2005 42 Sedan Bridge that presently has group 24 house batteries and i'm very suspicious (should they be group 27)???
My 2003 420 DA came with group 27.
 
I would have thrown myself overboard had I removed the 27's from my bilge floor and found the 31's would not work because of lack of cable length :)

Heavy and fit like a glove.

I think Group 27 is 12.5" and Group 31 is 13". I did measure the battery trays before purchasing.

So good point on making sure they fit before purchasing or changing batteries.


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He said group 24, they are only 10 1/4 long, so there would be no easy fix if the boat was set up for the 24's.

I agree, check your manual.

Does anyone have 24's for house batteries?

MM
 
Too funny . The dealer is responsible for the batteries up to a certain size vessel. My 34 and 44 had the wrong size batteries. Dealer woudnt budge , had to get searay involved. The manual specifically said they had the wrong batteries installed.

Rob
 
Too funny . The dealer is responsible for the batteries up to a certain size vessel. My 34 and 44 had the wrong size batteries. Dealer woudnt budge , had to get searay involved. The manual specifically said they had the wrong batteries installed.

Rob

Imagine how many times they get away with that??? I bet very few new boat buyers would ever check the size of the batteries at delivery. A nice way for the dealer to pocket a few extra bucks each year I suspect...
 
My 410 came with group 27’s, so did my old 300.
 
You Sea Ray guys are No. 1, Thanks, Were installing 7 group 31's and one 24 for the genny. We have 4 starting batteries for the Cummins 430 diamond series (2 each) and 3 group 31 house batteries and one group 24 for the gen set.
 
You Sea Ray guys are No. 1, Thanks, Were installing 7 group 31's and one 24 for the genny. We have 4 starting batteries for the Cummins 430 diamond series (2 each) and 3 group 31 house batteries and one group 24 for the gen set.

That will do it..

MM
 
You Sea Ray guys are No. 1, Thanks, Were installing 7 group 31's and one 24 for the genny. We have 4 starting batteries for the Cummins 430 diamond series (2 each) and 3 group 31 house batteries and one group 24 for the gen set.

Going with the group 31’s was a smart move. I should have done that.
Separate house batteries?
I have 5 batteries in my bilge and couldn’t imagine where I would ever fit two more.
In the bilge I’ve got two for each motor, one for the genny.
Starboard bank handles that motor and anything 12 volt at the helm like electronics etc..
Port bank handles that motor and all the 12 volt creature comforts (anything not at the helm).
Genny just handles the genny.
I’ve got two AGM’s in series for the 24 volt Bow Thruster stashed under the floor in the cabin that were put there when the Thruster was added.
 
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I installed (4) 235 AH 6 Volt Crown Golf Cart batteries Jul-14-2009 in a series/parallel configuration for our house bank. I check them 3 times during each boating season & top up with distilled water as required. I also have an 18 Watt solar panel up on the dash that is plugged into a 12 VDC source that helps the cause especially when out on the hook. These batteries are still going strong after 9 years service. I hope that I didn't just jinx it.
 
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i'm not sure if I'm going out of place or if this is the right way to post a new question. (if not, please advise) but:

Hello All. We have 2005 42 Sedan Bridge that presently has group 24 house batteries and i'm very suspicious (should they be group 27)???

JoAna,

I have a 2004 420 DB and have (6) Group 31 batteries on my boat. (2) Port, (2) Starboard and (2) Bow Thruster (24 volts wired in series).
 
Wow. Going DOWN from 31s to 24s means you've cut your available amp hours by ALMOST 30%!
 

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