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Discussion Starter #1 (Edited)
Fellow Sailors!

I believe it's time to replace my house batteries and as usually it's difficult to choose.

I currently have two GC2 6volts installed in series, however I think it may be an overkill. I say that because I keep the boat on a mooring and use the engine about 10mins each sail about 3 days a week. I mainly race the boat in local regattas, but this weekend I plan on cruising. Thus my interest in replacing these damaged batteries.

My concerns are:

1. I don't have any charging source other than my 10min alternator run each time I sail.

2. I live in Miami and am aware that the high temperatures are deadly.

Are my concerns valid? Should I re-buy these big batteries once again considering the conditions?

As of now I'm leaning to re buy them again because the trays are all ready for them. So I would like to know what are the recommendations, which model/brand and where to buy?

Thanks, Alvaro.

Any Help is much appreciated.
 

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2 -6volt batteries is approx 220 ah or 110 usable. Not really very much at all. May be enough for you usage

Do a electrical diet. iE anchor light 1 amp re hour for 8 hours etc.
Batteries o need to be recharged back to 100 no matter what type to last
6 volts have thick pates an 12 volts so they handle more deep cycles and last longer
Just get inexpensive ones at Wal Mart
 

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2 6v of that amhr is better than a single 12V generally speaking. Even racing, going toa single 12V will not be that much wt difference to worry about it, unless you are trying to do a major diet on the boat as far as total wt goes.......

Stick with what you have, unless you think 2 12V size 24's will work.....not sure the total longevity is worth it, both ahr wise, and the literal how long the battery will last in months vs yrs!

Marty
 

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No matter what batteries you use if they are not properly recharged they will die a slow death from sulfation. If you are on a mooring you absolutely need a solar panel and charge controller to maintain your batteries. The rule of thumb is 3.5 amps of panel output minimum per 100 AH of battery capacity. A 200 AH bank would require double the solar panel output. If you can get by with 100 AH you will save yourself a lot of expense. A 60 to 70 watt panel should do for a 100 AH 12 volt bank.
 

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A boat that has a typical cruisers load (lights, radios, maybe a plotter, frige perhaps) will take from one to three hours of alternator charging per day of use to keep topped off. When you're crusing, that probably won't be a problem. However, the other posters are right about prematurely killing your batts, if you let them die otherwise. Solar is the best idea. I suspect you don't use many amps when racing, so you may be able to get away with a fairly small and simply set up to keep the batt topped while away. I'm assuming a day of racing isn't draining them much. Maybe even detachable for race day.
 

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Fellow Sailors!

I believe it's time to replace my house batteries and as usually it's difficult to choose.

I currently have two GC2 6volts installed in series, however I think it may be an overkill. I say that because I keep the boat on a mooring and use the engine about 10mins each sail about 3 days a week. I mainly race the boat in local regattas, but this weekend I plan on cruising. Thus my interest in replacing these damaged batteries.

My concerns are:

1. I don't have any charging source other than my 10min alternator run each time I sail.

2. I live in Miami and am aware that the high temperatures are deadly.

Are my concerns valid? Should I re-buy these big batteries once again considering the conditions?

As of now I'm leaning to re buy them again because the trays are all ready for them. So I would like to know what are the recommendations, which model/brand and where to buy?

Thanks, Alvaro.

Any Help is much appreciated.

You have a few things to think about or that are issues:

#1 Heat: Where you boat is a problem just due to the high temps. Anything over 80F and batteries begin to lose life. Heat also leads to significantly faster "self discharge" so even if you got back to 80% SOC with the alternator the heat chewing into capacity at a significantly faster rate then batteries that remains in the 60's & 70's...

Unfortunately you can't do much about the heat, it is just a fact of life for where you live. AGM's would self discharge more slowly but then bring on a whole hose of other issues such as even shorter life, in your situation, and much more added cost come replacement time.

#2 Poor Charging: Lack of "full" chargers lead to sulfation of the battery plates. Sulfation becomes considerably more aggressive at anything other than 100% SOC +/- a few %. Sulfation is like battery cancer. Once it starts it only compounds until the battery dies. You can do periodic equalization charges but would need shore power. Equalizations are like Chemotherapy. It helps, but also degrades the battery via plate erosion... Best way to fight off battery cancer, on a mooring, is to keep the batteries full via solar.

Heat only speeds and compounds the sulfation issue and 20 min is doing very, very little to even replace what you used in Ah capacity. Even if you ran the motor for 2-3 hours you're still barely getting above 85% state of charge due to acceptance issues. This side of the equation you can change and you can add solar to deal with this and help minimize sulfation.

#3 Cost: There are a few options here. Spend some money on a small solar array (30W+) and leave it connected when you are not there. Depending on the array size in 2-5 days the batteries will eventually get from 80% to full. Once a week "full" for batteries helps tremendously. This can easily double the useful life of the batteries and also give you more reliable batteries that you can depend on.

The other option is to just accept the short life and live with it., many do. If that is the case the "big" 6V batteries are still going to be your least expensive option and may last two years+...

6V golf cart batteries deal with "abusive" situation better than their 12V cousins and as such last longer in the same abusive environment. They are also the least expensive battery to buy on a $$ to / Ah / longevity calculation. Heck they are usually the cheapest battery you can buy anyway. You can buy a pair of 6V batteries for $160.00 if you shop around. Having more Ah capacity is NEVER a bad thing especially when the batteries receive less than optimal charging..


My suggestion:

Stick with the 6V batteries and buy the new ones from a major golf course supplier, Sam's Club or Costco. Expect to pay $80.00 or less ea for a 6V GC2 battery, especially in Florida, the land of inexpensive 6V batteries.......
 

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Discussion Starter #7
Thanks All for the rapid responses.

Im planning on going out a buy the two 6Volts once again.

I remember reading a post from MaineSail and he had written that Sams club is now offering a good quality GC2 for a very decent price, those that still hold to be true? If not, where would be the recommended store or brand to purchase these?

I see plenty of discussion between which brand to buy, but it's hard to see the discussions reaching a common opinion.


Few options are: Diehard sold at Sears, Duracell Sold at Sams Club and I know costco also carries them, however I don't know the brand or specs.
 

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Thanks All for the rapid responses.

Im planning on going out a buy the two 6Volts once again.

I remember reading a post from MaineSail and he had written that Sams club is now offering a good quality GC2 for a very decent price, those that still hold to be true? If not, where would be the recommended store or brand to purchase these?

I see plenty of discussion between which brand to buy, but it's hard to see the discussions reaching a common opinion.


Few options are: Diehard sold at Sears, Duracell Sold at Sams Club and I know costco also carries them, however I don't know the brand or specs.
For your use/abuse brand matters less than cost. The least expensive GC2 6V battery you can find will be fine...
 

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Discussion Starter #9
Thank you all for the help!

Today I bought two interstate Gc-2s at Costco for 89 each and have a eating of 208ah. They were both dated 02/2013 which I assume is still considered new in comparison to the others that were dated 12/2012.

However I am now in doubt if they come charged?

Also, after reading Mainesail's post about the direction the batteries shall be installed.... The terminal in the stern-aft direction. My current setup is the opposite, the way it shouldn't be. Is there anything I can do to improve the condition, other than making a new tray and finding a new location for them?

I suppose that the greater the amount of water the more likely to keep the plates submerged, is that acceptable?


Thanks!!
 

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They are probably close to fully charged.

When wiring two 6 volts in series you wire from the negative post on one to the positive post on the other. That leaves a positive post on one battery and a negative post on the other - you can't wire them wrong. Ideally the batteries will be positioned with the long way port to starboard.

You want the liquid level to be over the plates but not much higher. If the plates are covered now I wouldn't add water but would put them on a charge until they reach 100%.
 

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I just replaced mine w/an Interstate DC27 Marine. Rated at 180 ah at 25a and told it had near half again the cycles at the next lowest (160ah/$117.) one @ 300...so 450 cycles!
Was listed at $150.75. I got another 10% off 'cause I bought a new batt for the vehicle at the same time. Pays ta ask for a discount! :D Will be my primary/only batt, as my Beta 20 only takes a couple hundred cranking amps ta start ;)
 

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I just replaced mine w/an Interstate DC27 Marine. Rated at 180 ah at 25a and told it had near half again the cycles at the next lowest (160ah/$117.) one @ 300...so 450 cycles!

You are confusing Ah capacity and reserve capacity, they are not the same thing.

You have 180 minutes at 25A before the battery is dead or about 3 hours. Course you never want to completely kill the battery (a reserve capacity test takes the battery to 10.5V) so really you have about 1.5 hours at 25A.....

This is NOT the same as having a battery with 180Ah's. There is no such animal as a group 27 battery with 180Ah's or even 160Ah's for that matter. The average group 27 battery will have between 80 and 100Ah's of capacity at the 20 hour rate.
 

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Thanks for the clarification, MS
as read from the label;
Pro 27M ECL series
CCA625, MCA 845; assuming that's cranking amps?
RC 180
RCC 100

So.. the second number...RRC100 is the one to look at; 100 min @ 25A ???
Is the time and amps linear? IOW would that be the same as 1000 min @ 2.5A ??

My meager energy budget is only (proposed) to be near to 5a/hr while running lites are on and when anchoring and interior lites are on; perhaps 3a....LED's run "cheap", yanno ;) I don't plan of running the monitor while away from shore power; but, w/associated electronics might run 4a.
Approx 7a divided into the 25a =3.57 X 100 min/60 works out to all but 6 hours before I enter trouble zone and need ta recharge.
Close? Did I get it near ta right?

:D
 

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I'm in the process of putting in 4 six volt batteries. I've used 2 in a series but looking for how to wire up 4. Know positive to negative. Do you hook up the actual feeds off positive and negative at the opposite ends of the chain. Also thinking about making it six if I can squeeze them in which I think will work. Have Balmar high output alternator. Later down the road want to add solar or wind
Thanks

Last Mango
Endeavour 38
Mobile AL
 

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I'm in the process of putting in 4 six volt batteries. I've used 2 in a series but looking for how to wire up 4. Know positive to negative. Do you hook up the actual feeds off positive and negative at the opposite ends of the chain. Also thinking about making it six if I can squeeze them in which I think will work. Have Balmar high output alternator. Later down the road want to add solar or wind
Thanks

Last Mango
Endeavour 38
Mobile AL
http://www.batteriesinaflash.com/wiring-your-battery-bank-in-series-parallel-and-series-parallel

Make sure you use the positive off one end of he bank and the negative off he other end of he bank to the panel so the batteries are used equally.
 
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I second MaineSail's point about getting a small solar panel.

On my first boat (Victory 21), I had a flexible solar panel strapped to the cabin top. Whenever I went for a weekly sail, the battery bank would be fully charged. The panel was small enough that I didn't need a charge controller.

And, IMHO, solar is a simple way to occasionally get the battery fully topped off.

Regards,
Brad

Regards,
Brad
 
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