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Replacing the House Batteries -- Choices??

Feb 19, 2015
6
Hunter 310 San Diego
I purchased a 1998 Hunter 310 3 years ago and had no battery issues until they died this week (they're over 6 years old). The previous owner had a "house battery" series/parallel 12 volt set up using two sets of two deep cycle 6 volt batteries (4 total) with 232 Amp hours at 20 hrs each (Interstate brand). I'm told that this set up is best as it provides the longest power supply. I'm not an electrician and know nothing about what batteries are the best for the power needs of the Hunter 310. The replacement Interstate Batteries with the same specs are $150 per battery. Costco has a 6 volt RV battery rated at 208 Amp hours at 20 hrs (also Interstate) for $84 per battery, Is it acceptable to go with 208 Amp hours vs. 232 Amp hours to save 40%?? Help!! Thanks!
 
Jul 7, 2004
7,305
Hunter 30T Cheney, KS
I don't believe ALL of them died. Try to figure out which is the culprit. I'd keep the same ratings on all if it were me.
 
Aug 2, 2009
427
Catalina 28MKII Muskegon
Your battery capacity has much less to do with your boat, than it does with how you use your boat (your own personal energy requirements).

To really arrive at your needs would require you to do the math. What does each device draw, and for how long? But, maybe you don't want to do that.

I use my 28 foot Catalina as a daysailor with the occasional overnight, but usually when we take a trip, we get a slip. And, no refrigeration. I'm perfectly happy with a pair of so-called deep cycle 12v batteries, each on it's separate bank. I had a bank of 6v's on my previous boat when we traveled more.

If you're sort of a "casual" user, as I described above, then you could take the easy way out, skip the math, and save the 40%. Nothing wrong with that approach.

I guess if it was me, and my boat was already configured for 6v banks, and I had a general idea of whether the existing setup fit my needs, I'd still go for the larger capacity. It doesn't seem like a lot more to pay for the additional capacity.
 
Jan 19, 2010
9,019
Hunter 26 Charleston
How do you recharge your batteries? Do you have shore power? Or a trickle solar panel?

Six years seems like you got your money's worth however, batteries will last longer if you don't run them too deep between charges. I keep a small solar panel on my boat and I have shore power as a charging option. I try not to let my batteries run down at all and I really only use them to run fans and lights. I have about the same batter capacity as you described. You do want deep cycle batteries. A car battery used for cranking will not last long because they are not designed to be drawn down.
 

tgrady

.
Nov 22, 2013
53
Hunter 33.5 North Vancouver
6 years is good for flooded batteries if they were taken care of (water added, good charger, etc). Definitely go for AGM type minimum. 6 volt golfs are good. Do not just get rid of the bad battery because it will be out of balance for the charger. I am doing some replacement myself and am going with .....Fireflys! Expensive initially but last a lot longer and can be discharged lower without sulfating!. Good if you want to keep your boat over 5 years. I am getting 3 and they only come in 12 volt. Might want to check up on your charger also.
 
Feb 19, 2015
6
Hunter 310 San Diego
Thanks. But I think they all died. We had a long period of bad weather and I failed to start the engine regularly for over two months. They were bone dry and when I filled them with distilled water they didn't hold a charge. They were all at least 6 years old and had come with the boat.
 
Feb 19, 2015
6
Hunter 310 San Diego
How do you recharge your batteries? Do you have shore power? Or a trickle solar panel?

Six years seems like you got your money's worth however, batteries will last longer if you don't run them too deep between charges. I keep a small solar panel on my boat and I have shore power as a charging option. I try not to let my batteries run down at all and I really only use them to run fans and lights. I have about the same batter capacity as you described. You do want deep cycle batteries. A car battery used for cranking will not last long because they are not designed to be drawn down.
I recharge with the battery charger on board using shore power. It was never a problem for the three years I since I purchased the boat. I'm a weekend boater and am usually connected to shore power at the marina. I never had battery issues with my day sailing trips in the bay. I neglected to maintain the batteries (my bad) and check the water levels before it was too late.
 
Feb 19, 2015
6
Hunter 310 San Diego
Your battery capacity has much less to do with your boat, than it does with how you use your boat (your own personal energy requirements).

To really arrive at your needs would require you to do the math. What does each device draw, and for how long? But, maybe you don't want to do that.

I use my 28 foot Catalina as a daysailor with the occasional overnight, but usually when we take a trip, we get a slip. And, no refrigeration. I'm perfectly happy with a pair of so-called deep cycle 12v batteries, each on it's separate bank. I had a bank of 6v's on my previous boat when we traveled more.

If you're sort of a "casual" user, as I described above, then you could take the easy way out, skip the math, and save the 40%. Nothing wrong with that approach.

I guess if it was me, and my boat was already configured for 6v banks, and I had a general idea of whether the existing setup fit my needs, I'd still go for the larger capacity. It doesn't seem like a lot more to pay for the additional capacity.
I am a casual user and probably wouldn't be able to do the math even if I wanted to. I have the usual electrical equip for this type of boat-- standard small fridge, stereo, nav, cabin lighting. Nothing that draws too much power. I'll probably just replace what I have with the same since I'm too much of an electrical neophyte to be sure that if I go with 208 amp hours vs. 238 amp hours that I'll come up short just when I need power. Thanks.
 
Oct 22, 2014
13,883
CAL 35 Cruiser moored EVERETT WA
Nothing that draws too much power
The reason for the exercise (even if you are not perfect) is to get an idea how much of a total draw you have with everything on.

It is like death by a 1000 cuts. None of the equipment does much impact alone but add them up and you could have dead batteries in 24 hours.

I had an AIS transponder using 2 watt max transmitting power. Left boat with charger on about 4pm Sunday Jan 29th. Could see the boat on the Vessel Finder app. Then at 4:29 AM Friday Feb 3rd. the AIS was no longer transmitting. That 2 watt transmitter had depleted the 140 AmpHr batteries.

So it is a little for a long time or a lot for a short time. Only you and your boat can tell.
 
Feb 17, 2013
53
Hunter 380 Port Clinton, Ohio
I just bought 4 230 amp hour 6 volt batteries from "Batteries Plus Bulbs" in Toledo Ohio. Highly rated. $109. each, And get 10% off if you order online and pick up in store. See below.
Duracell Ultra High Capacity Battery for Trojan T125
SLIGC115

42 Reviews
  • 12 Month Free Replacement Warranty
  • 6V high capacity Deep Cycle power
  • 230AH at 20 hour rate
Brand: Duracell Ultra
Voltage: 6
Format: BCI Group GC2
Lead Acid Type: Deep Cycle
 
Jan 19, 2010
9,019
Hunter 26 Charleston
I recharge with the battery charger on board using shore power. It was never a problem for the three years I since I purchased the boat. I'm a weekend boater and am usually connected to shore power at the marina. I never had battery issues with my day sailing trips in the bay. I neglected to maintain the batteries (my bad) and check the water levels before it was too late.
Oh well.... at 6 years you were probably due anyway.
 
Jan 22, 2008
7,890
Beneteau 323 Annapolis MD
My B32 has 3 x 31 batteries. Overnight I only have two batteries working for the house. Every other weekend my club does an overnighter. Normally 3 or 4 of us use 40 Ah overnight , but 50 if we are running the fans. V, you're only talking 24 between the cheaper and more expensive batteries. Considering you'd us no more than 50 percent of you Ah, you're really talking very little juice foe a lot more money. I got my deep Duracells at Sam's club. I went there to buy two, but the low price allowed me to get three.
 
Last edited:
Apr 8, 2010
1,485
Ericson Yachts Olson 34 Portland OR
We replaced our 9 year old house bank (two 6 volt Trojan flooded batteries) last year. They stopped holding a charge. We were on an early-season overnight cruise and woke up to find that the bank was down to 10.5.
The fridge was still running but was probably about to stop due to a low voltage situation. We switched over to our spare "emergency" 12 volt battery and started the engine. That battery is even older, and still holds a charge with no problem, but it's an Optima AGM, and has a near-zero self discharge rate.
With two new Trojan T-145+ six volt batteries installed, we are good for many more years. (Knock on wood!)
For a 31 footer with all the usual modern electrical bits and pieces, I would certainly not want any less amp-hours.
I also added a Balmar Smartgauge, and it is wonderful reading the voltage of both "banks" and also the charge level of the house bank.
I put up a blog entry for this little project.
http://www.ericsonyachts.org/infoexchange/entry.php?485-2016-New-Batteries-New-Smartgauge

Regards,
Loren
 
Oct 29, 2012
266
Catalina 30 TRBS MkII Milwaukee
Why reinvent the wheel or this case a system that obviously worked well for over six years and possibly more had proper maintenance observed.
 
Feb 2, 2015
14
Ericson 35-2 Penetang, ON
If I am understanding correctly, I cannot fathom how ALL the batteries could possibly go 'bone dry' in only two months. The only way this can happen is if they split or are boiled off due to significant overcharging. Batteries can be left for two years with the caps on and not go bone dry. There is something else happening here.
 

tgrady

.
Nov 22, 2013
53
Hunter 33.5 North Vancouver
It is my understanding that you can kill batteries if left hooked up. And flooded batteries need to be checked weekly/monthly for water and periodically for correct concentration . Sometimes you can recovery a bit by a careful overcharging routine that is available in some of the better chargers (something about shaking the sulfate off). AGM's are relatively maintenance free hence their value. You can still kill them by a complete drain and of course an overcharge. There is a ton of information out there about this but because it is "just batteries" and electricity nobody reads it until it is to late.
 
Mar 3, 2003
703
Hunter 356 Grand Rivers
Getting three years off lead acid batteries is good, 6 is outstanding. If it were me, I would replace it with what you have even though the amp hour difference is very small, but so is the cost. You should only deplete them 50% before recharging to get maximum life. The difference at 50% discharge of approximately 30 amp hours (15 at 50%) could have been one of the reasons you got so many years out of the system. If you get an extra year or possibly 3, you are saving big time for going larger.
 

BarryL

.
May 21, 2004
782
C&C 110 Mt. Sinai, NY
Hello,

You will be fine with the costco batteries. You won't even notice the (very) slight difference in capacity. I assume you that the new costco batteries will have MORE power than your older interstate batteries. Your old batteries had been loosing power since new and probably had significantly less power for the past few years. If you didn't have a problem for the last three years you won't have a problem with new costco batteries.

I just went through a similar excersize. I have 3 batteries on my boat and they all died this winter. They are from 2010 so it was time. I replaced one battery with a costco interstate 27DC. My costco doesnt carry 6V batteries so I bought 2 interstate GC2 ECL 6V batteries for $141 each. The costco batteries are much cheaper.

Barry
 
Oct 8, 2013
30
Beneteau 321 1999 Rose Haven, MD
West has an electrical worksheet which will guide you through the process of figuring out how you use your boat's power systems - this is standard stuff if you take a marine electrical 101 class. Having had similar problems, as others here have suggested, I'd have a long sideways look at your shore charger, if the batteries were boiled down to nothing in two months. You can spend a little or a lot on that piece, but they are more and more sophisticated these days, and it you are working off of the OEM model, $200 for a modern model would probably be a very good way to spend 'boat units'.