Battery advice, please?

[Captain Dharma]

Hi Everyone - I'm nearing the end of refitting my 1984 Present 38 trunk deck trawler and it's time to build the house bank. I estimate that the highest daily amp hour consumption would be about 300ah with an average daily of 175-250ah. The goal for the House Bank is 650 amp hours total. My mechanic and I are wondering which batteries to buy? Oh, I'm 68 years old so I only need a set of batteries that will last me 8-10 years at most.

I inherited a new 390ah dual purpose Barracuda AGM Bank that starts the Lehman 120s and feeds the exterior and interior LED lights. I think that these are rebranded Delcos and that my alternator can keep up with this load, but I don't want to add anything else to that bank until I know more.

Other than the refrigerator, the House Bank will mostly feed the AIMS 3000 watt pure sine wave inverter/charger. The inverter will feed two MacBooks, two iPhones, microwave, toaster oven, and other small electrical stuff. Am I overestimating the size of the House Bank I need?

Is there a modestly priced option to build a bank of about 650ah that a non-techie like me can live with? There isn't room for six (6) group 31s so we're looking at three (3) AGM 4Ds with 200ah at around $370 apiece, but I'm open to suggestion. A local (Jacksonville) distributer has AC Delco 4Ds at a decent price. Are AC Delcos OK or should I run away? I can pick up batteries anywhere in northern Florida or southern Georgia.

Space in the engine room is limited. There is a 22"L x 12"W x 10"H box under the floor boards between the Lehman 120s but anything taller than 8" means I will need to reroute some hoses.

I hope that this all made sense. I've read everything I can, but I've never done this before and I tend to err on the side of overkill. I hope to add solar panels later, but only if I need to run the KiloPac 8Kw generator more than a couple hours a day - preferably while on the move. Ultimately my wife and I are headed for the Bahamas and want to sit silently on the hook for a couple of weeks at a time. Thanks for your help.

[TheThunderbird]

Hello Captain!

May I get onboard for my 2cents!?

Your calculations are more than ample...

I would ADD a service (house ) bank AGM separate from current engine (multipurpose?) bank, which is still efficient, I understand.

Buy a battery monitor (Bogart best, or Victron, or...) as it is MANDATORY to control SOC and to top up the bank as much frequently as possible (I mean 99%, not daily 85%)

Consider solar at least for floating and topping up, mainly when boat is unattended.
Pretending to go fully green, with your consumption.. would be expensive. Start with say... 350W solar

I WISH YOU WILL BE CONSIDERING AGAIN WHICH BATTERIES TO BUY, 10YEARS AHEAD OF NOW :-)

FAIR SEAS to Captain and Admiral

[Captain Dharma]

Hi - Thanks for your response.

As you suggest, I'm setting up a completely parallel House Bank and not asking the Starting Bank to do anything, but start the engines and Generator. I have a ProMariner charger and remote taking care of the Starting Bank.

I have a Balmar Smart Gauge to monitor the House Bank.

The House Bank will feed an AIMS 3000 watt pure sine wave inverter. I need 225ah daily to do normal stuff. I have guests coming for 4-5 days in March, but usually it's just the two of us.

I have a KiloPak 8kw Generator to recharge the House Bank while running.

Now I need batteries to store the energy. My new figure is that I need at least 600ah total. Trojan T105s are wonderful, but too expensive at $400/300ah. What else have people done? I've found the 12v Duracell Ultra High Capacity Battery with 230ah for $109. It's a golf cart battery, but cheap.

[socaldmax]

Originally Posted by Captain Dharma

Hi - Thanks for your response.

As you suggest, I'm setting up a completely parallel House Bank and not asking the Starting Bank to do anything, but start the engines and Generator. I have a ProMariner charger and remote taking care of the Starting Bank.

I have a Balmar Smart Gauge to monitor the House Bank.

The House Bank will feed an AIMS 3000 watt pure sine wave inverter. I need 225ah daily to do normal stuff. I have guests coming for 4-5 days in March, but usually it's just the two of us.

I have a KiloPak 8kw Generator to recharge the House Bank while running.

Now I need batteries to store the energy. My new figure is that I need at least 600ah total. Trojan T105s are wonderful, but too expensive at $400/300ah. What else have people done? I've found the 12v Duracell Ultra High Capacity Battery with 230ah for $109. It's a golf cart battery, but cheap.

If you don't mind golf cart batteries, they're still the best bang for the buck. Costco or Sam's Club sells them for about $83 ea, plus $15 core charge.

I think they're all standard size, I'm familiar with the Costco ones, made by Interstate. They're 7" wide x 11" long and about 10" tall. They're 225AH ea, so you'd need 6 to get 675AH (about 335 usable), I'd recommend 8 to give you 450 usable AH. This would make the batteries last much longer, since you wouldn't be discharging them as low as a 675AH bank.

[TheThunderbird]

I envy your battery market
Nothing here comes any cheaper than 1,55EUR/Ah (AGM DEEP CYCLE)

Golf cart are widely available there, and have strong reputation on CF, but.. they may create problems if you're short of space.
Maybe.. a 3x200Ah set is better, but have you the guys for handling them!? They'd be 100+lbs each... vs 75lbs approx for a 150Ah battery.

BTW !! Your gen is good at 8kw, but the real bottleneck is the charger! With a 40% DoD or 250Ah to be refilled, and a 80A charger, in 3hrs you are still well short of topping up, as resistance increases, and your ears are boggled too! That's why some solar push is a benefit

[smac999]

I would look at golf carts or L16 if you have the height. both of these are available in AGM. generally avoid "car" batteries for a house. (24,27,31,4d, 8d etc) non of these are real deep cycle. I doubt you'll get 8-10 years from an AGM house bank. maybe if you're lucky.


make sure you move all your lights and other stuff onto the new house bank. the engine batteries should have nothing on them but the engines.




with an AGM bank and a big gen I would add a 2nd big charger like another 100a. a 650ah agm bank will take ~200 amps. cut your gen run time in half each day.

[darylat8750]

I have a trawler similar to yours with electrical needs similar. I bought 8 golf cart batteries from Costco in Mexico 5 years ago and they worked very well. They were abused several times IE left to go completely flat because of failure of dock power with the refer. still going and then not recharged for several weeks after...... Still got through a couple more months at reduced capacity. There are several discussion threads here about "best bang for the buck" batteries. I recently bought these Duracell® Golf Car Battery - Group Size GC2 - Sam's Club The Duracell brand is not available in every state but in my opinion worth a little drive to get them. They are made in USA and have a very good reputation. You might get by with 6 of them but I think you would be happier with 8.

The original alternators on my Lehman 2715s could not charge up the bank from 16 hour anchor out unless I ran the engines at least 7 hours. I bought a 160 amp large frame bus type alternator and the difference is dramatic. The Lehman already has a double groove pulley on the crankshaft, a double groove for the alternator is an easy off the shelf item so the only one that is expensive is the double groove for the water pump. I can't over state how happy I am with this upgrade . If I move the boat for at least 4 hours between anchorages I don't need to run the genset at all.

Read Maine Sail's Compass Marine How to articles for good advice about wiring battery banks. http://www.marinehowto.com

[TheThunderbird]

Indeed... a 100A charger would cost more than the house bank !

Best is to install a power alternator of 150A approx. And, either use it for Bulk charge (inner regulation) or with a Balmar MC-614 for fine trimming/float.
Generator+charge would take care of absorption/floating.

I am planning for this, actually!

On a power boat the regulator looks necessary. But I avoid long logs under engine...

[a64pilot]

I have an AGM bank and I recommend against them for cruising.
I am AGM due to sizing constraints of the battery box, but they require being fully recharged at a min of a couple of times a week. And if yours allow it, equalizing monthly.
Great batteries for what I do now which is weekend cruise and a vacation once in awhile, but the rest of the time tied to a dock with shore power.
My opinion is if you have AGM, you need significant Solar, and my plan is to run the genny a couple times a week early in the morning to get through bulk phase and deep into absorption with the idea that when there is enough Sun, Solar can top them off.
Even in the tropics, even with unlimited Solar, due to acceptance rate, you can't get to 100% charge on Solar alone, just not enough time.
With no Solar, a couple of times a week the generator needs to run all day.

I believe 10 years is pretty uncommon for a bank, even if you do everything right, I believe 5 is closer to average.
With out going with significant Solar, and a big ole charger, it may make more sense to do what you have to to put in golf cart batteries with the idea of replacing them every few years as you'll likely be cycling them between 50% and 85%.

AGM are high $ batteries and will not last if you cycle them at partial charge more than a year or two.


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[pcmm]

STOP! Do not buy anymore batteries until you know what your daily usage is. To do that get a good battery monitor like a Victron BMV-702 they cost less than $200 and will tell you what you are really using.

Are your lights LED or conventional? get 12 adapters for your mac books and ipads/iphones the less you convert DC-AC-DC the better off you are!

Before you do anything you need to know what you consume on a daily basis away from the dock. remember its better to consume less than to purchase the infrastructure in order to be able to consume more!!!

There are lots of battery monitors on the market. Currently I think the best is the Balmar smart gauge ( a bit expensive), then the Victron, Xantrex and last the Bogart. the bogart comes in pieces and is a pretty old school unit( and expensive for what you get) If you can afford it get teh blamar, otherwise get the Victron

[btrayfors]

I agree with A64pilot, AGMs are NOT what you need. This is because of price (relatively expensive) but mostly because of their need to be FULLY charged frequently. For all practical purposes, this means either charging at dockside or having sufficient onboard solar power to reach a full charge every day or two.

Size of charger does not matter so much....ANY size charger is going to require many HOURS of charging to reach 100%. Yes, larger chargers will replace more energy faster than smaller ones, but that last push to get from, say, 85% or 90% to 100% takes HOURS since the battery in this stage will not accept much current.

I think your best bet would be 6V golf-carts in series/parallel. Six batteries will give you about 675-700AH capacity which would be plenty for your stated needs. And, golf-carts are true deep-cycle batteries which are more robust and will take more abuse than will AGMs or Gels.

However, flooded batteries need to be watched to be sure their electrolyte levels remain above the plates. This means adding distilled water (only) whenever the levels drop. HydroCap or WaterMiser caps can reduce the frequency of watering and make it easier to inspect/fill. A good investment.

After a couple of decades using Trojan T-105s, I switched two years ago to Crown Red-Top industrial golf-cart batteries. They are rated at 235AH and after two years cruising with them I'm very happy. They were about $100 each in Annapolis -- considerably less than the T-105s which in my opinion are sometimes (over)priced out of the market.

As I left my boat in Maine this winter, I removed the six Crown golf carts and brought them home with me. Here they are on constant charge in my basement. WaterMiser caps are fitted on each battery. BTW, they still test better than new!


Good luck.

Bill

[Captain Dharma]

Hello again! The combined wisdom of this group is invaluable and I want to thank all of you for sharing what you have learned.

At this point I am looking for 6-8 6v golf cart batteries to which I will add a watering system. My wife has agreed to let me put them under the port settee which is close to the inverter and close to the electrical panel. Trojans are expensive so I'm currently looking for Crown Red Tops near Jacksonville, Florida.

I will drive a reasonable distance to avoid shipping if possible. Where do I find the Crowns for the best price?

[a64pilot]

Down South here, I'm in Albany Ga myself, usually the best place to buy golf cart batteries is the local SAMs club.
Do try your best to have cores to turn in as I think that can add up quick.
Unless mistaken there may be a couple of different manufacturers that can be under the same label.
Don't get too hung up on a brand, seems Deca and East Penn I think make the SAMs club batteries I believe, but am not sure and both I believe are good batteries.

If money is the object, it's my belief that you can replace golf cart batteries three times in the next ten years and still be out way less money than if you go AGM and buy all the "stuff" necessary to keep them healthy, and you will have to replace them anyway once at least, in my opinion, as I think 10 year battery life on a full time cruiser is rare. I think many are getting by on banks that meet the definition of dead, but they are watchful of power and get by.

Now there are experts here, but I'm not one. Do you good to read some of Maine Sails thoughts, somebody have the link?


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[btrayfors]

Originally Posted by Captain Dharma

Hello again! The combined wisdom of this group is invaluable and I want to thank all of you for sharing what you have learned.

At this point I am looking for 6-8 6v golf cart batteries to which I will add a watering system. My wife has agreed to let me put them under the port settee which is close to the inverter and close to the electrical panel. Trojans are expensive so I'm currently looking for Crown Red Tops near Jacksonville, Florida.

I will drive a reasonable distance to avoid shipping if possible. Where do I find the Crowns for the best price?

John,

There must be a ton of dealers near Jacksonville. The Crown golf cart battery you are looking for is the GR-235.

Here are a few possibilities:

Florida Industrial Battery Jacksonville, FL, 32254 - YP.com

Swift Industrial Power

Crown Battery | Jeffrey Allen Inc.

Car & Truck Battery Products, New & Used Batteries in Jacksonville, FL

Google is your friend :-)

Bill

[Vasco]

My daily usage is about 75 amps. That's mostly the freezer/fridge. How do you use 225 amps daily? I have a smart phone, iPad and computer. All lighting led. Just wondering where all that power is going. By the way my house bank is 600 amps, Trojan 12 volt batteries , flooded.

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