4 six volts better than 2 twelve volts

[john61ct]

Originally Posted by hooligan6a

Two 6 volts are fine until one cell goes bad and then you no longer have 12 volts.
if you have 2- 12 volts and one cell goes bad you still have 12 volts. You can't start an engine on 6 volts

A backup for cranking the engine is better served with a Starter battery, very cheap. Or a lithium jumpstarter kept charged on the shelf.

But now we know OP can afford Rolls 12V, could go that way to accomplish both that goal and quality / longevity in his deep cycling bank.

But any other 12V FLA would not be worth the compromise.

Note also, two strings of 12V would also give redundancy.

[Sailorman Ed]

After manhandling an 8D out, we went with six 6v deep cycle from

Battery Plus ( I had a big spreadsheet to compare).
Two important points to consider. Be sure all your interconnect cables are exactly the same length - we had new ones made special by Custom Battery Cable Assembly Custom Made Genuinedealz.com
Second, because of limited space, put in a watering system https://www.flow-rite.com/battery-care/brands/pro-fill/
Easy to fill all at one time and little floats to prevent overfilling - well worth the cost.

very happy with result.
Ed

[GrowleyMonster]

Originally Posted by Sailorman Ed

After manhandling an 8D out, we went with six 6v deep cycle from

Battery Plus ( I had a big spreadsheet to compare).
Two important points to consider. Be sure all your interconnect cables are exactly the same length - we had new ones made special by Custom Battery Cable Assembly Custom Made Genuinedealz.com
Second, because of limited space, put in a watering system https://www.flow-rite.com/battery-care/brands/pro-fill/
Easy to fill all at one time and little floats to prevent overfilling - well worth the cost.

very happy with result.
Ed

I like it, in principle. But is there any chance of a malfunction? Overfill? I would prefer something a little more manual in nature, so as to be less of a potential failure point. Valves fail. Floats stick. Things happen. But this might be ideal for certain types of owners.

[sailor1924]

[QUOTE=CaptainJohn49;2795069]I have tried 6 volt gold cart batteries and I didn't like them.

"Problems I had:

3. I didn't get very long life out of my setup either. I got my batteries at Costco here in the USA. Nothing special, but certainly not real cheap ones either. Two years later they had to be replaced. This was my fault because they were in such a tight space that all cabling had to be removed to get the batteries out to check the water. This took about a half hour so I didn't do it often. Bad dog."

FLA batteries do need regular watering.
I've installed a remote watering system for my 6 volt batteries to avoid the hassels of difficult location. I'm very pleased and it takes almost no time to water up.

I'll second or third the comments about battery weight. A good 6 volt weighs about 67 pounds which is as n much as I want to handle even with my outboard gantry.

https://www.amazon.com/Flow-Rite-RV2...D87ZYH4WWBZTHJ

[fish53]

4D, 8D and six volt golf cart batteries aren't true deep cycle batteries.

[Stu Jackson]

Originally Posted by fish53

1. 4D, 8D and



2. six volt golf cart batteries aren't true deep cycle batteries.

1. correct


2. incorrect

[rsn48]

Well then price is obviously not a concern, and that changes everything.

I would advise starting a new thread titled appropriately for the specific topic, question you want answered, to attract more and better responses.

Would replacement fuel for your Efoy be readily available in your cruising grounds?


Price is a concern, I'd rather not spend it than do, but I have the money now and I can get batteries that will not be more expensive over the years, replaced much latter than regular batteries. This thread helped me struggle with what batteries to use. I started out lithium oriented, talked to a few people who said I could get batteries that could be taken down 80 % and be much cheaper. I was going to follow this option.

But I've reflected on my own personal experience. I haven't bought "normal" 'D,' 'AA,' 'AAA' batteries in decades because the old battery technology was junk. I own a RAV 4 hybrid and love it, but.... I'd prefer it had a lithium battery, I know why they didn't use one - price - but performance would even be better, where are the Chinese when you need them? I also own an electric bike, same deal, old battery technology, same reason - price - but performance suffers. Same with tools, if electric, lithium all the way. I'm always amazed that I can pull out some tool I haven't used for a year and a half and it still has a decent charge.

Back to price, if you watched or read the Wynn's web page you'll see that "ultimate" price isn't as radically more expensive than traditional batteries; its just you pay it all now. Kind of like the new Epson printer technology, new printers are doing away with cartridges and selling more ink in squeeze bottles much like the yellow mustard squeeze jobbies, the printer you can buy at Costco now promises two years of use out of the ink supplied with the printer. But you pay a price for this new technology able to provided cheaper ink. The companies philosophy is we can screw you now, but at a cheaper long term price, or you can buy our cheaper printers where you need new cartridges every ten minutes and we'll screw you more over the long term ownership of the printer.

Its because of idiots like me and the Wynn's that technology evolves, becomes more affordable, and definitely superior.

My first IBM XT desktop:https://en.wikipedia.org/wiki/IBM_Personal_Computer_XT

My first laptop, Toshiba released the first portable laptop to the world, 20 meg hard drive and back and white, text only, not back lit screen:

https://en.wikipedia.org/wiki/Toshiba_T1100

Efoy technology will evolve as well. Fortunately for me, just about every chandlery on Vancouver Island and the Vancouver Lower Mainland carry it. I know that two canisters will probably last a summer, and another two canisters will probably last the off season (I use my boats a lot between labour day and Victoria day - American translation: something like Memorial Day).

[john61ct]

Originally Posted by fish53

4D, 8D and six volt golf cart batteries aren't true deep cycle batteries.

Wrong, in every case exceptions exist.

In the last case, lots, in the former Rolls only, at least in NA.

Costco's GC's are JCI like Interstate, meh.

Deka and the other FLA I listed are top notch, especially wrt to value.

[fish53]

Originally Posted by Stu Jackson

1. correct


2. incorrect

According to Interstate and Trojan and having cut one open golf cart batteries are not true deep cycle batteries. The plates are too thin to constitute a true deep cycle battery as evidenced by the shorter recharge times which is what they're designed for.

[sailorboy1]

Isn’t it amazing that this topic comes up almost monthly and still gets the same responses mostly from the same people as it got the last 6+ times.

[fish53]

Originally Posted by john61ct

Wrong, in every case exceptions exist.

In the last case, lots, in the former Rolls only, at least in NA.

Costco's GC's are JCI like Interstate, meh.

Deka and the other FLA I listed are top notch, especially wrt to value.

There are no "exceptions", the plates of all of these are designed for shorter recharge times and more power available at discharge such as in starting a diesel engine or hauling fat golfers up a hill. That doesn't mean they won't work fine in your application.

[Montanan]

Originally Posted by KP44

I need to speak up here.

I am replacing my three 8D AGM batteries with eight 6 volt in series parallel. I used 6 volt before and they did well for 10 years.
I replaced with the 3 expensive AGMs (About $2,000, if I remember right.) and they gave me a smaller battery bank and nothing but problems. They did not seem to actually give the amp hours they were rated at. I have a 150 amp Ample Power alternator and an advanced Balmar regulator. The AGMs never seemed to have the storage they were rated at. (West Marine batteries.)
After a dismal season last year, I bought 8 new 6-volts to replace the AGMs. When I pulled them out, I found the sealed AGMs that "never leak and never boil over" had leaked and crumbled the floor beneath them. I cut out the acid-crumbled area yesterday and am replacing it.
I always used (home-made) battery boxes with the 6 volts. But since the AGMs are "sealed and never leak or give any problems", I strapped them directly to the floor. Big mistake; they do leak. I saw leakage down the sides of two of the three AGMs.
So I will be back up to about a 900 amp hour bank for half the cost of the undependable AGMs.
Just thought I need to share this.

AGMs are one of the classes of VRLA. They will vent gas and / or electrolyte when charging rates cause excess formation of gases than can be recombined. They are intended to be maintenance free for convenience purposes and can operate at an angle.

https://en.wikipedia.org/wiki/VRLA_battery

VRLA batteries have a pressure relief valve which will activate when the battery starts building pressure of hydrogen gas, generally a result of being recharged at a rapid rate. Valve activation allows some of the gas or electrolyte to escape, thus decreasing the overall capacity of the battery. And the escaped acid will be corrosive. Rectangular cells may have valves set to operate as low as 1 or 2 psi; round spiral cells, with metal external containers, can have valves set as high as 40 psi.

The cell covers typically have gas diffusers built into them that allow safe dispersal of any excess hydrogen that may be formed during overcharge. They are not permanently sealed, but are designated to be "maintenance free". They can be oriented in any manner, unlike normal lead–acid batteries, which must be kept upright to avoid acid spills and to keep the plates' orientation vertical. Cells may be operated with the plates horizontal (pancake style), which may improve cycle life.

At high overcharge currents, electrolysis of water occurs, expelling hydrogen and oxygen gas through the battery's valves. Care must be taken to prevent short circuits and rapid charging. Constant-voltage charging is the usual, most efficient and fastest charging method for VRLA batteries, although other methods can be used. VRLA batteries may be continually "float" charged at around 2.35 volts per cell at 25 °C. Some designs can be fast charged (1 hour) at high rates. Sustained charging at 2.7 V per cell will damage the cells. Constant-current overcharging at high rates (e.g., rates faster than restoring the rated capacity in three hours) will exceed the capacity of the cell to recombine hydrogen and oxygen.

[Palmer]

One thing that's important to consider is the inherent danger of connecting batteries in parallel. If one of them develops a problem, the good battery may dump a lot of current into the bad battery, making it hot or even causing a fire. Adding blocking diodes will prevent this problem.

[Rufduck]

So, back to OP but add the following...
Bank location impossible to access to service.
Not lazy, just old and want a trouble free (ha) house bank of about 400ah at 12v nominal.
Am willing to relocate house bank to under a port berth (good idea or not) for slightly better serviceability.
Currently have 3 group 31 SLR125 VMAX AGM Deep Cycle 12V 125AH. Plus a second pair of 12v AGM Group 31 paralleled for emergency engine start and a CPAP machine.
Installed in 36 ft cat.
Cheers.

[Adelie]

Originally Posted by rsn48

Was talking to a chap and told him of my possible battery acquisitions. He recommended I get 4 six volts, two wired in parallel, rather than 2 twelve volts. He said the 6 volt jobbies were better as part of battery function was dependent on size and the two 6 volts would offer more usage than an equivalent one 12 volt. Checking to see if this is true.

My understanding is that in general 6 volt golf cart batteries are better than 12v batteries.

In my case I only have room for 2 batteries so I opted for 12v batteries. This is because if I lose 1 cell in 1 battery I have reduced capacity at 12v coming off the other battery. If I have 2 6v batteries and lose a cell I might have just enough voltage to run some electronics or I may have nothing at all.