Batteries relocated on a Hunter 37.5

Apr 12, 2005
130
Hunter 37.5 Legend Catawba Island, Ohio
I have a 1995 Hunter 37.5 Legend and I am thinking about relocating the batteries to the space under the aft cabin cushions. I would like to have the aft locker for storage. Relocating the batteries would also remove that weight to a lower and more central location. I would like to hear your thoughts...
 
Feb 21, 2013
3,782
Hunter 46 Point Richmond, CA
Where are you relocating the batteries from? Moving the battery weight to a lower, ceneterline location is a good plan.
 
Apr 12, 2005
130
Hunter 37.5 Legend Catawba Island, Ohio
They are currently in the aft starboard cockpit locker.
 
Jan 18, 2021
45
Hunter 40.5 Burnt Store Marina
I am currently doing the same exact thing on my 40.5! Except a genset was placed in the starboard locker and batteries moved to port.

Just templated everything yesterday. The hulls curvature is more pronounced there and in the potential of any water sloshing around I am going to hang my battery boxes and inverter off of the top of the birth rather than on the hull.
 
Feb 10, 2004
3,510
Hunter 40.5 Warwick, RI
I am currently doing the same exact thing on my 40.5! Except a genset was placed in the starboard locker and batteries moved to port.

Just templated everything yesterday. The hulls curvature is more pronounced there and in the potential of any water sloshing around I am going to hang my battery boxes and inverter off of the top of the birth rather than on the hull.
So you are planning to sleep under several hundred pounds of batteries? And also reduce your overhead clearance to enter and exit?
 
Jan 18, 2021
45
Hunter 40.5 Burnt Store Marina
So you are planning to sleep under several hundred pounds of batteries? And also reduce your overhead clearance to enter and exit?
Lol. How do I described it...

Hang the batteries from under the board, under the mattress.
 
Feb 10, 2004
3,510
Hunter 40.5 Warwick, RI
Lol. How do I described it...

Hang the batteries from under the board, under the mattress.
OH, I completely misunderstood the battery location.
But now I am curious as to how you are going to physically install the batteries and connect them with cables? If they are FLA, how will you check/service them?
 
Oct 26, 2010
1,431
Hunter 40.5 Beaufort, SC
I am currently doing the same exact thing on my 40.5! Except a genset was placed in the starboard locker and batteries moved to port.

Just templated everything yesterday. The hulls curvature is more pronounced there and in the potential of any water sloshing around I am going to hang my battery boxes and inverter off of the top of the birth rather than on the hull.
I've been toying with this idea I have the same setup - Gen in stbd locker, 2 batteries in port locker - balances the added weight of the generator so I like them there. I would like to add two 6V golf cart batteries though and your proposed location sounds interesting. I don't know if I'd like "hang them" though. Where are you planningon putting them in under the aft berth. I"m thinking only the centerline are is deep enough so are you using the lift out hatch area just aft of the shaft compartment?

I'd be interested to see pictures of your template and proposed location. I'll let you blaze the trail.
 
Oct 26, 2010
1,431
Hunter 40.5 Beaufort, SC
@SandyFrank - Why are you worried about water sloshing around in that location? I've never seen water in there of any kind and I can't imagine how it would get there except a major leak of some sort? I do see though that you'd have to have some way to have them level with the hull curvature so they would have to set on something other than directly on the hull. Can you fit a battery box there with your template. Lots of questions here.
 
Jan 18, 2021
45
Hunter 40.5 Burnt Store Marina
OH, I completely misunderstood the battery location.
But now I am curious as to how you are going to physically install the batteries and connect them with cables? If they are FLA, how will you check/service them?
First caveat is these are going to be LifePo4 Batteries, about 560Ah worth. I am installing 2 x 280, but it seems like up to 5 x 280 could be installed under there... As long as they are sideways.

I've been toying with this idea I have the same setup - Gen in stbd locker, 2 batteries in port locker - balances the added weight of the generator so I like them there. I would like to add two 6V golf cart batteries though and your proposed location sounds interesting. I don't know if I'd like "hang them" though. Where are you planningon putting them in under the aft berth. I"m thinking only the centerline are is deep enough so are you using the lift out hatch area just aft of the shaft compartment?

I'd be interested to see pictures of your template and proposed location. I'll let you blaze the trail.
I will post some pictures after completion. The 280Ah lifepo4 I am using leave plenty of options, see a rudimentary diagram below. The only position that was questionable was the vertical one on the left as it runs over the exhaust. Green are the ones I am installing because of the genset.

Potential Battery Location(1).jpg



The PO *spits* was a terrible person electrician. I ripped out and rebuilt the entire AC side, including some scorched electrical tape splices hidden behind the fiberglass. So this upgrade is part of a complete rebuild of the DC side.

@SandyFrank - Why are you worried about water sloshing around in that location? I've never seen water in there of any kind and I can't imagine how it would get there except a major leak of some sort? I do see though that you'd have to have some way to have them level with the hull curvature so they would have to set on something other than directly on the hull. Can you fit a battery box there with your template. Lots of questions here.
Just being a little prudent when it comes to keeping the bilge pump running! The batteries are going to be installed with the terminals sideways, close to three seacocks and the raw water exhaust. I do sail the boat, so if on a starboard tack it seems prudent.
 

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Jan 18, 2021
45
Hunter 40.5 Burnt Store Marina
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83 days after ordering they have arrived!

Got my 1/2 starboard and should be installing this weekend.
 
Jan 18, 2021
45
Hunter 40.5 Burnt Store Marina
Pics of the final installation and details if you can.
Well... Not final but you can see it does infact fit. The BMS is going to be installed on the side of the battery box. Just waiting on a terminal post for the negative post for the BMS.

PXL_20210824_131508454.jpg

Just off the centerline.

PXL_20210824_130822208.jpg


Going against the drawer.
 
Jan 18, 2021
45
Hunter 40.5 Burnt Store Marina
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There you go. Part of a much bigger refit, wiring should be complete this weekend. The amount of wire I have pulled out of this boat...
 
Jan 7, 2014
258
Beneteau 45F5 51551 Port Jefferson
They are currently in the aft starboard cockpit locker.
When you move them pay attention to the orientation of the batteries. My trojan t-105's needed to be oriented with the terminals port/ starboard rather than bow/stern. Otherwise the plates could be exposed when you heel. I don't think AGMs have that problem and lithiums definitely not.

 
Nov 26, 2012
1,532
Hunter 34 Berkeley
I did this. Moved the batteries to the locker under the port settee right at mid ship. Much better. The main drawback is that I needed about 60 ft of battery cable which runs about ten bucks a foot.
 
Jan 18, 2021
45
Hunter 40.5 Burnt Store Marina
Battery installation complete.

PXL_20210918_202844751.jpg


Just waiting on USPS to deliver box 2 of 2 of 0/2 (red) cable to hook up to the new main electrical panel in the engine bay.