Battery advice for new-to-us Hunter 36...and why did these huge Northstar AGMs die so soon?

jssailem

SBO Weather and Forecasting Forum Jim & John
Oct 22, 2014
23,034
CAL 35 Cruiser #21 moored EVERETT WA
I concur @artboas .
It feels so simple. See a new exciting idea that owners are talking about. Throw your money down to be a part of the excitement. Only to discover there is more to the problem and more money is needed.

On the other hand if you approach the subject with a macro examination of the problem and possible solutions, you may find a lower cost old idea that resolves all of the issues including the fanciful claims of the new and exciting fad.

At present I want a battery storage system I can lift on board. I want the system to have flexibility, safety and redundancy. The system must be affordable. The function must match my anticipated needs and 80-90% foreseeable usage. Stored power needs to be able to come from on board systems. In place recycling strategies at end of life is desirable.
 

BarryL

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May 21, 2004
1,065
Jeanneau Sun Odyssey 409 Mt. Sinai, NY
HI,

I have one of those on my boat. I tested it on a car with a dead battery. It worked. It's small and light enough and cheap enough to be a 'no brainer' for me. On multiple occasions I have loaned jump packs to friends on boats. Fortunately, I have never needed mine but one of these days it will probably happen.

Barry


Hey gang-

As a purely interim measure until I get new batteries, is there any consensus on these very popular car jump-starter packs just in case?

Thanks!
 
Jan 11, 2014
12,861
Sabre 362 113 Fair Haven, NY
HI,

I have one of those on my boat. I tested it on a car with a dead battery. It worked. It's small and light enough and cheap enough to be a 'no brainer' for me. On multiple occasions I have loaned jump packs to friends on boats. Fortunately, I have never needed mine but one of these days it will probably happen.

Barry
Nah, you'll never need it because you have a jump pack on board. Leave it home sometime and sure as anything you'll need it. :biggrin::beer:
 
Jan 4, 2006
7,233
Hunter 310 West Vancouver, B.C.
Those batteries need to be charged with a 14.7V absorption and the recommended charge current is .4C or 40% of Ah capacity
Hi @Maine Sail . Is there a minimum charging rate for a battery bank with a three stage charger and sufficient time to get to a float charge. If there is a problem with going less than 0.4C, can you aim me towards anything that explains what the problems are ? Thanks.
 

Kupe

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Feb 28, 2021
32
Hunter 36 Lake Lanier, Atlanta
If there is a BatteriesPlus nearby check them out. I bought my Duracell Ultra GC2s from them. The Duracell's are available in a range from 215 Ah to 255 Ah. For the price point I went with the 230 Ah batteries.
BTW, The GC2 fit in the footprint of a Group 27 battery.
Great stuff thanks! I found your batteries in stock at a nearby Batteries Plus so going to drive by tomorrow just to have a look. I am a bit concerned about the footprint of 4 of these so I need to drive up to the boat as well to measure my battery box. Not having ever bought 6V batteries (and also not a golfer) I guess I assumed they would be smaller than a Group 27 12v. But I love the Ah specs on your GCs!

Curious too if BatteriesPlus will give me two core credits for the Northstars. I doubt they see batteries like that very often LOL!

Thanks again!
 
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Jan 11, 2014
12,861
Sabre 362 113 Fair Haven, NY
Four 6v GC batteries have roughly the same footprint of 2 Group 31s. The 31s are smaller than your 4Ds.

If they won't give you a core credit, look for a scrap metal yard. Last time I took in some batteries I got $8 a piece, a core return would only net me $5 a piece. The scrap yard will pay by weight.
 
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jssailem

SBO Weather and Forecasting Forum Jim & John
Oct 22, 2014
23,034
CAL 35 Cruiser #21 moored EVERETT WA
I assumed they would be smaller than a Group 27
NO... different - Taller.
GC battery= Weight:64 lbsLength:10.25 inWidth:7.125 inHeight:10.875 in

Grp27 battery= Weight:52.5 lbsLength:12.625 inWidth:6.75 inHeight:9 in
 

Kupe

.
Feb 28, 2021
32
Hunter 36 Lake Lanier, Atlanta
For the kind of sailing you'll be doing, the GCs are probably your best bet both in performance and cost. Be sure to measure to make certain they will fit and you should have a battery box for them to fit into. You'll also need a couple of jumper cables for the series connection. All that will cost less than one of the Northstar batteries.
Thanks Dave! I just cut out paper templates 10.25" x 7.125" for the Duracell Ultra GC2. Going to what-if it up at the boat hopefully this weekend.
 
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Kupe

.
Feb 28, 2021
32
Hunter 36 Lake Lanier, Atlanta
If they won't give you a core credit, look for a scrap metal yard. Last time I took in some batteries I got $8 a piece, a core return would only net me $5 a piece. The scrap yard will pay by weight.
Thanks! BatteriesPlus is offering a $27 core credit on their Duracell Ultra GC2. If they will honor that with the Northstars. But my back is such a mess I might be better served to pay a scrapper to just come pick them up at the boat.
 
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Apr 8, 2011
772
Hunter 40 Deale, MD
When I had to remove 4D batteries from my 356 I used a spare 3 part mainsheet with becket and cam. My batteries had web straps, which made it pretty easy to attach the tackle. There was some juggling with length of the travel of the system - did I mention I used the boom to make the lift. It came up easily and with the cam I could stop. It was basically one handed to lift and there was no back strain. I wanted to lift over the combing and swing the boom out over the dock. I couldn’t get the battery that high because of the web straps which were too long. I could have adjusted but by that time some he-men showed up and they weren’t about finesse.
Please don’t risk a back injury!
I'll second this approach. It's the same I used to lift out my two dead 4Ds in my 2009 H36 and it worked beautifully. The one difference in my approach was the boom remained fixed and I used my winches to pull the batteries over the cockpit seat (letting out a little line from the lift as the winches helped pull the battery over the seat). One person can do this very safely, a little at a time. Then I had a strapping neighbor help me get each one off the boat to a wheel barrow, and into the back of my SUV. With two people and the boat floating low to the dock at low tide this was reasonably easy and a very short distance.
 
Dec 25, 2000
5,930
Hunter Passage 42 Shelter Bay, WA
is there any consensus on these
Our boat has a starter battery and two 8D house bank batteries. In the off chance of needing an assist, I've got jumper cables and had to use them several years ago when our starter battery died due to old age. The house bank had enough oomph to get the main engine running for the short trip from Parks Bay to a Friday Harbor marine store to pick up a new battery. More than one way to skin a cat.
 
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Ward H

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Nov 7, 2011
3,778
Catalina 30 Mk II Cedar Creek, Bayville NJ
Yes, the Duracells are 11" tall - many boxes can't fit them.
Yes, very close. Actually 10.875" which is 1/4" shorter than T105s at 11.15" tall.
@Kupe Your NorthStar batteries show to be 12.6" tall so good chance GC2's, being a bit more than 1.6" shorter will fit.
 

Kupe

.
Feb 28, 2021
32
Hunter 36 Lake Lanier, Atlanta
Yes, very close. Actually 10.875" which is 1/4" shorter than T105s at 11.15" tall.
@Kupe Your NorthStar batteries show to be 12.6" tall so good chance GC2's, being a bit more than 1.6" shorter will fit.
Yep- and alas the lid of my battery box rests atop the Northstars....not ideal. I'm hoping the 1.6" will make the difference. Going to measure this weekend. Then next is to make sure I have a proper picture of the combo of serial and parallel jumper cables. Gahhh!
 

Kupe

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Feb 28, 2021
32
Hunter 36 Lake Lanier, Atlanta
Hey gang-

As you all have been so very generous with your knowledge...might any fellow Hunter 36 owners hazard a guess on what this wire is? I've highlighted with a red oval and question mark. By its shape it almost seems like some sort of data wire, but I don't think that's it. (The other set of fine smaller wires go to that little silver Nanopulser Desulfator). Thanks gang!
 

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Jan 11, 2014
12,861
Sabre 362 113 Fair Haven, NY
You are correct about the wire probably a data wire for a charger or battery monitor.
What is the nanopulsar? I’ve never heard of such a thing.
 
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Kupe

.
Feb 28, 2021
32
Hunter 36 Lake Lanier, Atlanta
You are correct about the wire probably a data wire for a charger or battery monitor.
Thanks! Now I'm wondering if it is specific to the Northstars or AGMs in general, and should I include it with the GC battery setup? I'm inclined to include it.

What is the nanopulsar? I’ve never heard of such a thing.
Me neither. It's this little doohickey Velcro'd to the side of one of the Northstars. I'm pretty sure not applicable for the flooded GCs but not sure.
 

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Jan 11, 2014
12,861
Sabre 362 113 Fair Haven, NY
I think the prior owner of your boat was long on money and short on understanding battery technology. The Nanopulser looks like snake oil to me. Their website is long on claims, short on describing what it does and the technology behind it, unless I missed something.

The other wire might be a temp sensor for the battery. Can you trace the wire back to its source? What kind of charger do you have? If you have a battery monitor, look at the back of it, does it have a cable like this attached? What kind of battery monitor do you have?