House batteries dying!

Jul 5, 2017
37
Hunter 44DS Cape Coral
We purchased a Hunter 44DS in Annapolis and proceeded south on the ICW. The house batteries seemed to not be able to bold a charge. It appears that the house batteries are a pair of mismatched 4D batteries. One is an Interstate Battery and the other a West Marine Dual Purpose 1280 battery. The dilemma is that we are headed south on the ICW in an effort to reach Florida. I don't want to replace the batteries just to kill another set. We don't have a generator, or solar yet and must rely on the batteries when at anchor to power the freezer, fridge and some lights including the anchor light. My question is if we had two good new 4D batteries, could we manage the fridge and freezer as to not harm the batteries until we can get to Florida and have solar installed.
 
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Oct 22, 2014
20,995
CAL 35 Cruiser #21 moored EVERETT WA
Would depend on the alternator your motor has attached. And the 110 AC charger system on the boat when attached to the marina system.
 
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May 24, 2004
7,129
CC 30 South Florida
What is the capacity of the batteries n Amp Hours (Ah) that you intend to purchase? What is the average power consumption in Amps (A) of your fridge/freezer? What is the rated output of your alternator in Amps (A)? To illustrate the calculations let me make some assumptions about your system, if the batteries have a combined capacity of 270Ah they can be safely discharged to 50% so you will have usable capacity of 135Ah before having to recharge. If your fridge/freezer consumes an average of 3.5A it will consume approximately 84A in a 24 hour period (perhaps better in winter ambient temperatures). An alternator rated for 75A may produce 60A in bulk rate after heat losses and inefficiencies. If the engine was ran for 8-9 hours in a 24 hour period it might be able to cover the anticipated usage of 84-90 Ah a day. If your specs are bellow my assumptions you will likely fall short. Now, if you would spend the night at a marina every 3rd night and have a chance to recharge batteries 10-12 hours from shorepower you should make it fine. Understand that the figures reflect a safe discharge limit of 50% for the batteries as your criteria is not to unduly harm them. There are things that you can do to reduce the power consumption of the fridge/freezer like packing pre-frozen items, limiting the number of times the lids are opened and pre-cooling the unit on shorepower prior to departure. A full fridge is more efficient than a half full one. There are other tricks like freezing water jugs to use up space as well as helping keep temperatures. Find the specs of your system, run your numbers and determine your approximate consumption and production and if and when it would be appropriate to spend a night at a marina. Hot showers and Restaurants are an added incentive.
 
Sep 25, 2008
7,076
Alden 50 Sarasota, Florida
. My question is if we had two good new 4D batteries, could we manage the fridge and freezer as to not harm the batteries until we can get to Florida and have solar installed.
Probably, as long as your alternator is working properly to charge the batteries while motoring.

Assuming you have a simple voltmeter, check at the battery terminals with the engine running first thing after starting the engine in the morning when the batteries are discharged from overnight use. You should see 13+ volts at the batteries.

The above is an over-simplification but is a good indicator. It won't tell you much except whether the alternator is functioning.
 
Jan 12, 2011
930
Hunter 410 full time cruiser
. My question is if we had two good new 4D batteries, could we manage the fridge and freezer as to not harm the batteries until we can get to Florida and have solar installed.
Without a doubt as long as your alternator and charger(assuming you go into a marina) is working and will recharge the batteries. When you motor does the voltage of the batteries increase, if so they are charging?

I would suspect you have at least 1 bad battery, probably the older one. If you can isolate them from each other and find out if one is bad you could just isolate it for the short term.
 
May 20, 2016
3,014
Catalina 36 MK1 94 Everett, WA
You’ll shorten the life of any battery charging them with non optimal charge profiles for the type of battery chemistry. Doesn’t matter if it’s a 120V shore charger or your alternator. Also keeping a battery in a partial state of charge is hard on them.

Les
 
Jul 5, 2017
37
Hunter 44DS Cape Coral
We have a Balmar 100 amp high output alternator.
The charger is a Mastervolt 12-40-3
 
Jul 5, 2017
37
Hunter 44DS Cape Coral
The fridge and freezer are original equipment on the 2004 Hunter DS. Anyone know the amp draw for fridge and freezer?
 
Sep 25, 2008
7,076
Alden 50 Sarasota, Florida
The fridge and freezer are original equipment on the 2004 Hunter DS. Anyone know the amp draw for fridge and freezer?
Generally around 50 amps/day each. You can estimate it quite loosely yourself simply by noting the current draw when both are on and assume a 50% duty cycle.
 
Jun 5, 2004
485
Hunter 44 Mystic, Ct
Jack,
I installed (4) 6 volt batteries on my 2005 H44. I did not go with the Trojans as they are a little taller and I was not sure that they would fit under the floorboards. again from a height perspective. I went with Crown batteries which had been previously reviewed by Maine Sail. We have the same alternator. The batteries have been in service for about 5 years. The bank provides about 450 Amp_hrs. I also have the original fridge and freezer and typically recharge the batteries once a day when at anchor.
 
Last edited:
Jul 5, 2017
37
Hunter 44DS Cape Coral
Thanks for the many informative reply’s. Due to circumstances we are going to have a marine electric co who will come to your boat and install the batteries. We unfortunately had a low Bridge take out our windex, VHF antenna and anchor light so we have a few other things to take of as well. Once we reach our home port all of these things will be easier and cheaper to repair.
 
Oct 22, 2014
20,995
CAL 35 Cruiser #21 moored EVERETT WA
Once we reach our home port all of these things will be easier and cheaper to repair.
Oh Jack. If it only could be true...
It is a dream that every boat owner has. Kind of like the mystical site "Brigadoon" in Scotland, or the "Land of Unicorns"in my daughters book. It is a "Sirens Song" that whispers in every boat owners ear... "if you make it to home port all will be well. The repairs will be easy and the cost just about nothing. The beer will be free flowing and all the women will smile at you. "​
Fair winds Jack and safe journey. Home port is just through the mist on the bay.
 
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Jul 5, 2017
37
Hunter 44DS Cape Coral
Your comment made my day. Especially after we went under a low bridge that also had a repair net that I didn’t see until my anchor light crashed to the deck and the windex was bent and not functional. Oh well it’s only money.

Thanks again for the humor.
 
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dakno

.
Jun 22, 2009
209
Hunter 41DS new orleans
Your original 4d batteries should have been agm's which don't vent gas so I would assume you should stick with agm's unless you verify your venting and the profile of your charger/inverter. Our H41 came with 3 4d agm's and will run fridge and freezer for a few days without dropping below 12.5v, which is getting into danger area
 
Jul 7, 2004
8,402
Hunter 30T Cheney, KS
Hijacking this thread for a moment. It might be helpful here:
I have 3 bad batteries. One for Start, two for House. I have a Sterling Procharger with an output wired to both(each) banks.
Is there a significant advantage to replacing the 2 12v House batteries with 4 6v batteries? I think I have the space.