1992 370DA: Battery Re-Location

jrybak

Dock Holiday
Feb 11, 2019
163
Lake Ozark, MO
Boat Info
92' Sundancer 370
Engines
7.4L Mercruisers
I am thinking of installing two large AGM batteries for the house bank in the forward compartment behind the flip-up mirror in front of the V Berth (anchor access) ..... has anyone tried this or see any reason this is a poor idea? The batteries will add approx 250lbs to the tip of the bow.

Do the batteries that get paralleled together in a bank need to be identical in CCAs, etc?
 
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You gotta be kidding. Batteries in a rope locker that leaks like a sieve when running in heavy seas? But that's just me. Probably will be just fine.
 
I have two big AGMs in a locker under the mattress of the v berth. They power my bow thruster but you could use the space for what you have in mind. When we wired them, they have their own master switch and charging bank.

We had to build a custom shelf for the batteries to sit on and glass the shelf to the hull.
 
IMG_4230.JPG
I have two big AGMs in a locker under the mattress of the v berth. They power my bow thruster but you could use the space for what you have in mind. When we wired them, they have their own master switch and charging bank.

We had to build a custom shelf for the batteries to sit on and glass the shelf to the hull.
The A/C for his boat is located there. And, it is one of the few storage spaces on a 370 Express. But, it would be a safer location than the rope locker.
 
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The A/C for his boat is located there. And, it is one of the few storage spaces on a 370 Express. But, it would be a safer location than the rope locker.

I thought the mid 90s 370 Sundancer had two compartments under the mattress like the 370 Express....are you saying that isn't the case? I have one for the AC and another smaller one that is on the v berth side of the anchor line bulkhead....perfect for the bow thruster batteries.
 
Silly question - absent a bow thruster why do you want to move them? If you're looking for weight on the bow a much, much cheaper alternative would be to go to an all chain anchor rode.
 
Do not put lead acid or AGM batteries anywhere in your cabin... when charging they can off gas hydrogen... a very dangerous gas.

And besides that, you would need some very large gauge cable to deliver the 500 cranking amps to start your engines.

They put the batteries in the bilge, close to the engines for the above reasons.
 
IMG_4230.JPG
I thought the mid 90s 370 Sundancer had two compartments under the mattress like the 370 Express....are you saying that isn't the case? I have one for the AC and another smaller one that is on the v berth side of the anchor line bulkhead....perfect for the bow thruster batteries.[/QUOTE/]


I believe they are the same. My point was the general lack of storage for a boat that size would give me pause about using it for mechanical/electrical space and eliminating badly needed storage. I also wonder about the vibration and pounding that goes on up there and what that does to an expensive battery and possibly to the hull from the weight of the batteries going up and down and sideways even though they would be secured.
 
Do not put lead acid or AGM batteries anywhere in your cabin... when charging they can off gas hydrogen... a very dangerous gas.

And besides that, you would need some very large gauge cable to deliver the 500 cranking amps to start your engines.

They put the batteries in the bilge, close to the engines for the above reasons.

Jim,

My bow thruster batteries are both AGMs and both reside in secured, vented battery boxes located near the thruster in a forward compartment. The vent goes to the rode locker which is vented to the outside of the hull. It is a common location to place thruster batteries. While it is true AGMs will vent hydrogen.......that is only if they are being overcharged. Before I bought AGMs....I upgraded the battery charger.

I wouldn't put starting batteries that far forward.....but I would consider House batteries. The bigger question is why? If you want more weight.....as previously noted by Stee6403......an all chain rode will solve that problem.
 
I was just looking for a location to secure some additional larger AGM batteries for the house bank. The weight upfront was not my intent but I wanted to ensure it wouldn’t be an issue.
 
I thought the mid 90s 370 Sundancer had two compartments under the mattress like the 370 Express....are you saying that isn't the case? I have one for the AC and another smaller one that is on the v berth side of the anchor line bulkhead....perfect for the bow thruster batteries.
I have no storage at all in that area, under the mattress is the water tank in about the middle and Aft of that is the the AC unit. I don’t have any access panels toward the bow in front of the water tank.
 
location concerns aside, yes, they would be wired in parallel, and yes they should be of the same size, type and vintage.
 
Thinking of going with (4) Odyssey Extreme 31M-PC2150ST Batteries for the starboard / house bank, and a fifth one for the port side motor starter.
 
Thinking of going with (4) Odyssey Extreme 31M-PC2150ST Batteries for the starboard / house bank, and a fifth one for the port side motor starter.

I’m not sure that will work with your charger and the starboard alternator.

Just for clarification, don’t you currently have 3 battery banks: 2 bats (starboard/house), 1 port, 1 generator?
 
Yes i do have that current setup. I am also installing a new Victron eng skylla ip44 Charger.

the charger and alternator should see the bank as a huge AH 12V battery.
 
If Victron says it will work .....that is great. I'm just concerned if you somehow deplete your four battery bank.....it may take a while to recharge it.
 

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