Forums General Discussion What kind of batteries are you using and where are you buying them?

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    • #222427
      Ryan Doyle

      Hello all,

      We just closed on our new-to-us P424 in December, and I’m working on the surveyor’s punch list as well as some upgrades. Her batteries are 12 years old, so it’s time to replace them.

      She currently has one large lead acid start battery:
      (Interstate Workaholic 4D-XHD 1250 cranking amps

      And 4 golf cart style Energizer EGC2 6v batteries for the house:

      The boat has a Westerbeke 58 with a standard alternator as well as a 150 amp alternator that came with the boat that I need to hook back up. I’m also planning to install a 200w solar kit for now, then later expand the solar array and the house battery bank in the future to handle refrigeration.

      With this in mind, does anyone have any suggestions on battery types, brands, and retailers? I’m curious what battery setups you all are having luck with out there…

      Any input is greatly appreciated!

      Thanks in advance.


    • #222429
      john stevenson
      Battery discussions are only slightly less contentious than anchor discussions.  Everyone has a preferred battery and a preferred configuration.
      I'm sure you are aware that batteries are only 1/3 of the electrical system that must be sized as a unit.  The other factors are the average load that you will place on the batteries and the charging capacity.  All three must by in sync,  So someone who powers all of the on board electrical systems via 12VDC using an inverter for the AC loads  may require a huge battery bank and charging capacity using solar, wind and water chargers.  A fossil fuel Luddite, such as myself, who runs the AC loads off a generator, needs a much smaller battery and charging capacity, but of course larger fuel tanks.  So my battery configuration may not match your needs
      That said, I have a preference for Trojan T105 6v batteries.  I have 4 in my house bank.  I use a generic Grp 24 battery for engine start (Yanmar 4JHAE).  I last purchased  the T-105 from a dealer in Green Cove Springs, FL for $100 each.  That was the best price I could find nationally, and I saved more by being able to pick them up rather having them shipped.  Unfortunately, that dealer went out of business last year.  Maybe that price really was too good.  So I can't recommend a retailer.  If you are in a popular golfing area check out the golf cart dealers in addition to marine suppliers.  Golfers seem to be more frugal than sailors and demand better prices.

    • #222431

      I have 630ah (6 105s). If you’re looking for the best deal, I don’t know that you can do better than West Marine’s store batteries (DEKA rebranded) on a port supply (West marine pro) discount.

      I seem to have more than enough power with a stand alone fridge (power hungry at 6amps), these batteries, and 400w of solar. Not terribly expensive either – I think 840 for the batteries total.

      Pearson 424 cutter - "Effie"

    • #222432
      Dennis Home

      I use a large starting battery like yours and 4 trojan 6 volt batteries with a a large 130 amp alternator and have not “ plugged in” in years.


    • #222434
      Ryan Doyle

      Thanks very much for the responses. I really appreciate it. I should have mentioned here that my electrical needs are fairly low at the moment – just cabin and nav lighting (slowly converting all to LED) and a new Raymarine mfd and radar. I rarely use my inverter.

      Just an FYI – I posted this question earlier over at Cruisers Forum in case anyone reads that and thinks they’re having deja vu. I’ve gotten more responses from both than I thought I would.

      I’m now on the hunt for a some Trojan 105 golf cart batteries…

    • #222435
      Check out the Trojans T125.  Next size up from the 105s, just a bit taller but more Ahs. 

    • #222436

      The subject of battery power can be somewhat a religious discussion like anchoring.  I can tell you what works for me but I may not use my boat the same way you will use yours so your needs may be different.  I keep my boat on a mooring and almost never plug into shore power.  I spend a lot of time on the boat during the summer and depend on my batteries to keep the boat livable.  I have engine-driven refrigeration and my lighting is almost all LED.  Most of my power use goes to running the TV and satellite dish.  I watch a few hours of TV each night.  The entertainment system consumes about 10A when on.  There are other power consumers on the boat, my computer, wifi, radios, and lights.  The engine must be run twice each day for a total of about 90 minutes to keep the refrigerator cold.  This 90 minutes keeps up with my power consumption.


      I have a set of solar panels mounted on the top of my davits.  They are nice and help produce power but are not really intended to keep up with my power demands.  I use about 100AH/day.  Solar panels can’t be depended on for that kind of power unless you have a huge solar array and huge batteries.  My solar panels are responsible for topping-off my batteries when I leave the boat for a few days.


      My 424 originally came with a pair of 6D deep-cycle batteries.  This proved inadequate.  If the house batteries ran down, I couldn’t start the engine.  I had to reserve one bank for starting and one for house use.   I now use four 220AH 6V golf-cart batteries for a total bank size of 440AH.  I get mine at Sam’s club.  There are better batteries out there but they can cost an arm and a leg.  Mine last a half-dozen or more years.  I replace them after about that much time, not because they go bad but because they are on a replacement schedule.  If I do something bad to them and have to replace them earlier I don’t lose a huge investment.  For a starter battery, I have the biggest car starter battery that Sam’s sells.  The 4D battery you now have is rather small.  The GC2 battery bank IMHO is a better choice if you can find a place to mount them.  Mine are in the bilge under the main cabin sole.


      I have two alternators on the engine.  An industrial 160A alternator for the house bank and the stock 55A alternator for the starter battery.  The advantage to having two battery banks is that even if I discharge the house bank, I know I’ll be able to start the engine.  I see that you have two banks.  For this to work, you must keep the banks separated. There are a number of ways to do this.  I have two alternators.  It could also be done with a battery combiner or a solenoid switch. 


      The solenoid switch method is the least expensive and most reliable way to do this.  The alternator is connected to the house bank.  And the starter battery is of course connected to the starter.  You put an RV solenoid switch in your charging system so that when the switch is closed the starter battery gets connected to the house bank.  A 6V relay is attached to the tach output of the alternator.  When the engine starts, it energizes this relay coil and closes this small relay.  This in-turn provides power to the solenoid switch which connects the starter battery to your charging circuit.  The relay must be a 6V coil, not 12V because the tach output is half-wave; effectively 6V.


      Putting a huge alternator on your engine may not be the best choice.  Your batteries will only absorb enough current to drive the plate voltage up to the regulator set-point.  When depleted, the batteries may absorb all the charging circuit will give, so for a few minutes the huge alternator will actually put out its rated capacity.  After a few minutes the battery absorption rate will drop-off and may reduce to 50 A or less and eventually taper off to almost nothing.  The initial load put on the belts however is the maximum rating of the alternator.  A 160A alternator may need 4HP or more during startup.  This puts a huge load on the belts.  In my case, the refrigerator compressor also provides a load.  I have dual-belts and still have maintenance issues with them.  The rating for a good industrial alternator is measured hot, so if your alternator is cold and you start charging depleted batteries, your actual load might be considerably higher.  I estimate my startup load at 6HP.  If your alternator is a modified car alternator, it may not be robust enough to run at its full load rating for extended periods of time.


      A smart-regulator can reduce charge time by extending the time that your batteries will accept a full charge.  This can reduce the charge time of your batteries from several hours to one or two hours.  A good smart regulator can limit the max output of your alternator to less than its rating.  This improves belt life but extends charge time a bit.  Reducing the alternator output also keeps it cooler and extends alternator life.  A very large alternator with a smart regulator is considered the way to go, but you need to size the system, including the belts, correctly.


      Hope this helps.




    • #222439

      Hey John,


      One other part of that electrical system equation is how you use your boat. Weekenders have different needs than marina live-aboard’s than anchorage dwellers than long-gone cruising sailors. If I just wanted to live aboard in a marina with shore power and maybe go out for an occasional overnight sail on the weekend, I’d opt for a couple of Walmart specials. Who cares? Living aboard at anchor, probably something like what you’ve got. Gone with the wind? A big-bucks, long-life gold-plater like Lifeline, if the budget allowed. But you still have to crunch the numbers to know how many amp hours you’ll need.




      Silverheels 424#17






    • #222447
      Ryan Doyle

      Thank you guys. I really appreciate the input. There is a smart regulator on the boat.

      My wife and I are starting out with short cruises: Upper Chesapeake to NYC, then NYC to Maine in July. We will spend most of our nights on the hook. We are not full time cruisers yet, and our boat stays on a mooring.

      I ended up finding an amazing deal on 4 new Duracell golf cart batteries ($80 each) and a new house start battery ($100) at Sam’s Club. I’m going to start with 4 GC’s and possibly go up to 6 later. My battery box is currently built for 4.

      I’m curious if anyone here has used a Group 27 as a start battery with any luck? The $100 unit at Sam’s Club is a Duracell with 1050CA. A gentleman I’ve talked to has one starting the same W58 I have and it’s been more than adequate for him.


    • #222448
      I have a group 27 AGM for start battery just installed in sept works fine I also have 2 4d for house bank.
       SV Cygnus/spell Bound #80

    • #222463

      SV Patricia Bess came with 3 Interstate 4Ds, Two starboard (house), One stern (starting).In the spring of 2016 I replaced them with 3 Universal Power UB-4D (from China), tied together to make up the house bank 600 Ah. I added a Costco group 42 under the berth next to the started motor, as an independent cranking battery.
      The batteries are switched to hook the house to the starter if needed.
      I have a Honda 2000 generator to charge house bank if i’m on a mooring for any amount of time. All four new bateries cost about $1100. I’ll let you know how this set up works out in a few years.
      SV Patricia Bess #218

    • #222464
      Andrew Franklin

      I see you found a good deal (congrats great price), but I’ll add this in case someone else comes along.

      We have 8 Trojan t-145+ 6v golf cart batteries making a 1040ah house bank. This is also our starting bank. We are a very power hungry boat- huge fridge and freezer, lots of fans, radar, TV, xbox (2 kids and we are liveaboard cruisers), etc. We have 400w wind gen, 340w solar, and a 100a Balmar alternator. Plus a Honda 2000 suitcase gen to power the washing machine and water maker on laundry day.

      The Trojans are 7 years old now, and specific gravity tests show nearly same as new (thanks to PO for meticulous records).

      I’ve also used Trojans in industrial applications. There are cheaper options, but I don’t know of anyone who has paid the extra for the Trojan brand and been disappointed.

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