I am planning to replace the batteries on my H 335. The existing setup is the basic 2x12 volt deep cycle batteries. I have read in many postings that owners have switched to 6 volt golf cart batteries run in series and wondered what the reason for this was? I am guessing that its because it easier to locate two smaller 6 volt battery than one large 12 volt.
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More POWER Scotty!
Colin: I think what you will see is the fact that a 6 volt battery is 180-225 amps. So it takes 2 of them to give you 12 volts and the same amperage. Of course if you need 360-450 you just need 4 of them. Anyway to make my point, you can make more amps in a smaller foot print. You will need to go to 4D or 8D 12 volt batteries to come anywhere close to this. With your current setup you have a total of about 200 amps (estimate). You could leave a 12 volt for the starter and then add a bank of 6 volts to give you the reserve that you want.
Colin: I think what you will see is the fact that a 6 volt battery is 180-225 amps. So it takes 2 of them to give you 12 volts and the same amperage. Of course if you need 360-450 you just need 4 of them. Anyway to make my point, you can make more amps in a smaller foot print. You will need to go to 4D or 8D 12 volt batteries to come anywhere close to this. With your current setup you have a total of about 200 amps (estimate). You could leave a 12 volt for the starter and then add a bank of 6 volts to give you the reserve that you want.
Also Sturdier
They're also somewhat sturdier than the typical marine battery (heavier duty plates, etc.) and, although I haven't checked recently, are somewhat cheaper per amp hour. The only drawback I can see is that they probably won't fit in the typical battery box without modification. The two should be located right next to each other to minimize the length of the wire connecting the two together. I've been thinking about converting to 1- 12v 2- 6v when my current batteries need replacing.
They're also somewhat sturdier than the typical marine battery (heavier duty plates, etc.) and, although I haven't checked recently, are somewhat cheaper per amp hour. The only drawback I can see is that they probably won't fit in the typical battery box without modification. The two should be located right next to each other to minimize the length of the wire connecting the two together. I've been thinking about converting to 1- 12v 2- 6v when my current batteries need replacing.
Another 6V question
Regarding amp hours, hypothetically if I have 2 6V batteries rated at 50Ah each wired in series, is the total 100Ah 12V? Or is it 50Ah 12V? I have 6 golf cart batteries for my house bank, and the rated capacity by adding the listed Ah per battery is about 800. Since they are 6V do I really have 400Ah 12V?
Regarding amp hours, hypothetically if I have 2 6V batteries rated at 50Ah each wired in series, is the total 100Ah 12V? Or is it 50Ah 12V? I have 6 golf cart batteries for my house bank, and the rated capacity by adding the listed Ah per battery is about 800. Since they are 6V do I really have 400Ah 12V?
You still have 50ah at 12volts
To the fellow asking about 2 6v @ 50ah batteries in series, you still would have 50 amps only now at 12v. The only way to double the amps is to hook the batteries in parallel. That keeps the volts the same but doubles the amps. So what you could do is take 2 6volts put them in series and make one 12v then do the same with another pair of 6vs and hook that pair up in parallel with the first pair. That would double the amps and give you 12volts. Good luck Jack
To the fellow asking about 2 6v @ 50ah batteries in series, you still would have 50 amps only now at 12v. The only way to double the amps is to hook the batteries in parallel. That keeps the volts the same but doubles the amps. So what you could do is take 2 6volts put them in series and make one 12v then do the same with another pair of 6vs and hook that pair up in parallel with the first pair. That would double the amps and give you 12volts. Good luck Jack
Cheap and Powerful
1. The golf carts are cheap and powerful. Buy them by the pair and they run between $55 and $69 each (last time I checked prices was about five years ago). 2. The footprint is the same as a Group 24 but their height is 11 3/8-in vice 9 to 10-in for typical 24's. A pair of golf carts is about the footprint of a 4D. 3. Weight: 24s run about 55-lbs, golf carts about 61-lbs, and 4Ds 140 lbs. Since lugging batteries on board is difficult, getting them from the dock to the cockpit, and then down below, the golf carts make it much easier than a 4D because they come in "two parts", so to speak. 4. Cycles: Golf Carts are said to run in the 700 cycle range (50-percent discharge) but there are many indications that they will go far beyond that, even as high as 1500 cycles! Other batteries seem to have difficulty reaching their "rated" cycles. 5. Voltage drop with time: According to a graph of voltage vs cycle (time) one graph I saw showed the golf cart voltage holding up really well before a steep dropoff at the end of its life. Many other battery types have a decreasing voltage with time which is not as good. Our four carts are now 8 years old and the voltage a day after charging is still over 12.6 as measured with a Fluke digital multitester. That's good. 6. Compare cost at $/amp-hr/cycle and the carts win hands-down. 7. Construction: The reason for the extra height is to provide space under the plates for sludge so they don't short out as fast. The carts also have thicker plates than Group 24s. Wire them up with marine grade 00 cables and they'll work really great for you. A good 1000W inverter or better and high-output alternator with 3 step regulator are good accessories. Downside: They are not listed as "marine" batteries therefore try to keep the mast pointed up. They do give off H2 gas so keep them in an enclosure away from sparks. Also, I checked this site under "Site Search" for "golf cart", exact phrase - came up with 21 hits. Colin, if you've got the space this is a real easy decision!! Link: http://www.trojan-battery.com/default.htm
1. The golf carts are cheap and powerful. Buy them by the pair and they run between $55 and $69 each (last time I checked prices was about five years ago). 2. The footprint is the same as a Group 24 but their height is 11 3/8-in vice 9 to 10-in for typical 24's. A pair of golf carts is about the footprint of a 4D. 3. Weight: 24s run about 55-lbs, golf carts about 61-lbs, and 4Ds 140 lbs. Since lugging batteries on board is difficult, getting them from the dock to the cockpit, and then down below, the golf carts make it much easier than a 4D because they come in "two parts", so to speak. 4. Cycles: Golf Carts are said to run in the 700 cycle range (50-percent discharge) but there are many indications that they will go far beyond that, even as high as 1500 cycles! Other batteries seem to have difficulty reaching their "rated" cycles. 5. Voltage drop with time: According to a graph of voltage vs cycle (time) one graph I saw showed the golf cart voltage holding up really well before a steep dropoff at the end of its life. Many other battery types have a decreasing voltage with time which is not as good. Our four carts are now 8 years old and the voltage a day after charging is still over 12.6 as measured with a Fluke digital multitester. That's good. 6. Compare cost at $/amp-hr/cycle and the carts win hands-down. 7. Construction: The reason for the extra height is to provide space under the plates for sludge so they don't short out as fast. The carts also have thicker plates than Group 24s. Wire them up with marine grade 00 cables and they'll work really great for you. A good 1000W inverter or better and high-output alternator with 3 step regulator are good accessories. Downside: They are not listed as "marine" batteries therefore try to keep the mast pointed up. They do give off H2 gas so keep them in an enclosure away from sparks. Also, I checked this site under "Site Search" for "golf cart", exact phrase - came up with 21 hits. Colin, if you've got the space this is a real easy decision!! Link: http://www.trojan-battery.com/default.htm
Agree with John...more thoughts on 6 V batteries
I agree with almost everything John says, but would add that good golf car batteries can weigh more than 61 pounds. The extra weight is extra lead, which will either give you more amp hours per cycle, or more cycles. The reason that golf car batteries work so well is that they are designed for a huge market, indeed the ONLY mass market for battery powered vehicles. Technically, they differ slightly from a Marine Deep Cycle battery, but not in any important way. They are designed to be used hard, and in bumpy conditions, so they are structurally strong, as well. You can use a group 24 battery case, but the lid won't quite go all the way down. Finally, as a twenty-plus year slave in the golf industry, I can tell you that Trojan is the brand of choice...not Rolls, nor Surrette, nor any other. And, the best deals can usually be had from a golf car supplier, rather than a Marine Store, including West Marine. Good luck. This IS a no-brainer.
I agree with almost everything John says, but would add that good golf car batteries can weigh more than 61 pounds. The extra weight is extra lead, which will either give you more amp hours per cycle, or more cycles. The reason that golf car batteries work so well is that they are designed for a huge market, indeed the ONLY mass market for battery powered vehicles. Technically, they differ slightly from a Marine Deep Cycle battery, but not in any important way. They are designed to be used hard, and in bumpy conditions, so they are structurally strong, as well. You can use a group 24 battery case, but the lid won't quite go all the way down. Finally, as a twenty-plus year slave in the golf industry, I can tell you that Trojan is the brand of choice...not Rolls, nor Surrette, nor any other. And, the best deals can usually be had from a golf car supplier, rather than a Marine Store, including West Marine. Good luck. This IS a no-brainer.
The Big Question is......!
If they are so good in every respect, including costs, why don't boat manufacturers put them in all new boats?
If they are so good in every respect, including costs, why don't boat manufacturers put them in all new boats?
The answer may be.....
that golf car batteries wired in series, as they must be, are a bit more complicated for the user....and maybe the liability issues scare off the manufacturers. Additionally, golf car batteries imply a much greater capacity than the manufacturers of sailboats usually deliver, so maybe their marketing departments veto it. And finally, even though golf car batteries are very cost effective, they are still more expensive than the manufacturers' cost for the el cheapo group 24's or 27's that most boats come with! Again, I suggest that better guidance is provided by the golf car industry, whose market measures in the hundreds of thousands of vehicles, annually, which is, uh, a bit more than our sailboat industry produces. In addition, most golf cars are, in effect, rental vehicles, so there is a much greater incentive for efficiency and cost effectiveness, than in our sport....(sailing.....efficiency?...hummmm!)
that golf car batteries wired in series, as they must be, are a bit more complicated for the user....and maybe the liability issues scare off the manufacturers. Additionally, golf car batteries imply a much greater capacity than the manufacturers of sailboats usually deliver, so maybe their marketing departments veto it. And finally, even though golf car batteries are very cost effective, they are still more expensive than the manufacturers' cost for the el cheapo group 24's or 27's that most boats come with! Again, I suggest that better guidance is provided by the golf car industry, whose market measures in the hundreds of thousands of vehicles, annually, which is, uh, a bit more than our sailboat industry produces. In addition, most golf cars are, in effect, rental vehicles, so there is a much greater incentive for efficiency and cost effectiveness, than in our sport....(sailing.....efficiency?...hummmm!)
Why I use them
I have purchased Golf Car Batterys from Sams Wholesale for $45.00 per $90 a pair. Thats 210 amp hours! A set of 4 will give you 420 amp hours! The BIG Differance is that Golf car batts may be run down VERY LOW and STILL crank the motor! I have used my boat (Lights,Refrigerator) for three days and the batts started the motor very easyly! I am very impressed!!!
I have purchased Golf Car Batterys from Sams Wholesale for $45.00 per $90 a pair. Thats 210 amp hours! A set of 4 will give you 420 amp hours! The BIG Differance is that Golf car batts may be run down VERY LOW and STILL crank the motor! I have used my boat (Lights,Refrigerator) for three days and the batts started the motor very easyly! I am very impressed!!!
I'm Sooo Confused....
OK, talk me through this like the idiot I am. While I know a lot about my boat, I have not yet mastered the electricity part, it is on this year's list. I own a Passage 42. One starter battery and 2 house batteries...standard Hunter size. Are these 8d's or 4 D's? They are shot, I know because I pretty much ruined them. I need to replace them. How many amp hours do I have? If I replace with 4-6 volts, how many will I have? How do I hook up the 6 volt batteries to work, please tell me battery 1 /- to battery 2 /- to ..... In a Passage 42 with standard boxes, will the 6 volt fit? If not, what kind of modification needed? Can/should I buy new boxes? Where do I buy the 6 volt batteries, any difference in brands (I am not a golfer, all I know about golf carts is not to hit them when they are crossing the road) Sorry to be dumb here, but you guys have always been helpful in the past, I am just confused. Thanks so much!
OK, talk me through this like the idiot I am. While I know a lot about my boat, I have not yet mastered the electricity part, it is on this year's list. I own a Passage 42. One starter battery and 2 house batteries...standard Hunter size. Are these 8d's or 4 D's? They are shot, I know because I pretty much ruined them. I need to replace them. How many amp hours do I have? If I replace with 4-6 volts, how many will I have? How do I hook up the 6 volt batteries to work, please tell me battery 1 /- to battery 2 /- to ..... In a Passage 42 with standard boxes, will the 6 volt fit? If not, what kind of modification needed? Can/should I buy new boxes? Where do I buy the 6 volt batteries, any difference in brands (I am not a golfer, all I know about golf carts is not to hit them when they are crossing the road) Sorry to be dumb here, but you guys have always been helpful in the past, I am just confused. Thanks so much!
Series/Parallel Connections
The 4Ds have about 175AH each at 12 v. I am not sure about the 8Ds but they are bigger in size so should have more AH. I had 2 4D with 350AHs total in my C-36 MKII which I replaced with 4 6 v batteries with 470AH total. 120 AH more. The two 6v batteries did not fit in my 4D battery tray. If I had got the 225AH version they would have fit in the trays. I was trying get as much AH in my space as I could so I cut the trays to fit the batteries. You connect the batterys in series/parallel as follows: of batt 1 to - of batt 2 of batt 3 to - of batt 4 - of batt 1 to - of batt 3 of batt 2 to of batt 4 Boat System ground (BLK) to - of batt 3 Boat System Positive (RED) to of batt 2 This will give you 12v with 450 to 470 AH Hope this helps Rich Lemieux Amitie, C-36 1621 Noank, CT Fleet 5
The 4Ds have about 175AH each at 12 v. I am not sure about the 8Ds but they are bigger in size so should have more AH. I had 2 4D with 350AHs total in my C-36 MKII which I replaced with 4 6 v batteries with 470AH total. 120 AH more. The two 6v batteries did not fit in my 4D battery tray. If I had got the 225AH version they would have fit in the trays. I was trying get as much AH in my space as I could so I cut the trays to fit the batteries. You connect the batterys in series/parallel as follows: of batt 1 to - of batt 2 of batt 3 to - of batt 4 - of batt 1 to - of batt 3 of batt 2 to of batt 4 Boat System ground (BLK) to - of batt 3 Boat System Positive (RED) to of batt 2 This will give you 12v with 450 to 470 AH Hope this helps Rich Lemieux Amitie, C-36 1621 Noank, CT Fleet 5
P42 batteries
The factory house battery config is two 8Ds at roughly 225 AH each, 450 total. this give you a usable 225 if you follow the 50% rule. It would take 2 6V is series to approximately equal each 8D. If you do the measurements, 2 6V will not fit properly into the battery boxes on a 42. Wiring would be positive of bat 1 to neg of bat 2, pos of bat 2 to inverter draw selector switch, neg of bat 1 to ground. similar arrangement for bat 3 and 4. Nigel Calder's book would be a good place to start learning about electrics. There is a drawing, search the photo archive for windlass, of the wiring arrangement for a P42. Just replace each batt wirh 2 6V in series.
The factory house battery config is two 8Ds at roughly 225 AH each, 450 total. this give you a usable 225 if you follow the 50% rule. It would take 2 6V is series to approximately equal each 8D. If you do the measurements, 2 6V will not fit properly into the battery boxes on a 42. Wiring would be positive of bat 1 to neg of bat 2, pos of bat 2 to inverter draw selector switch, neg of bat 1 to ground. similar arrangement for bat 3 and 4. Nigel Calder's book would be a good place to start learning about electrics. There is a drawing, search the photo archive for windlass, of the wiring arrangement for a P42. Just replace each batt wirh 2 6V in series.
followup
Remember to imagine your boat on her side or worse when you are installing batteries or modifying the boxes. Be sure they are secure and the fluids are somewhat confined. Also be sure you can easily get to them for maintenance and electrolyte replacement. If you make it too difficult, it will be easy to say in effect ... i'll check tomorrow,. The savings you see can quickly evaporate.
Remember to imagine your boat on her side or worse when you are installing batteries or modifying the boxes. Be sure they are secure and the fluids are somewhat confined. Also be sure you can easily get to them for maintenance and electrolyte replacement. If you make it too difficult, it will be easy to say in effect ... i'll check tomorrow,. The savings you see can quickly evaporate.
wait a minute Bill!
I think with the 50% rule you are going to need 4 6V 220amp to give you the same usable power as the 2 8D's. Correct me if I'm wrong.
I think with the 50% rule you are going to need 4 6V 220amp to give you the same usable power as the 2 8D's. Correct me if I'm wrong.
go 12v agm
l would go 12v agm batterys less weight.no fluid check can be put in any position. They drain very slow. to many cables with 6 volt
l would go 12v agm batterys less weight.no fluid check can be put in any position. They drain very slow. to many cables with 6 volt
Don, I'll give you 3 reasons
Price, Cost and value.......;-) Really the relative Amp/hours per dollar are not lower than what I have seen for Golf Cart Batteries. So if you want the most bang for your buck.....go with the golf cart. AGM's are great but VERY expensive for truly deep cycle purposes. Try pricing out a a 200 AmpHour AGM !...(not cheap).....most are much lower amphours (and even then they are only a little lighter for the real deep cycle AGM's) The upside of the AGM is as you said. They can be mounted in almost position and really no maintenance whatsover. Both will last relatively long(# of cycles).....But my gut feeling is that the Golf Cart's will take even more abuse. (kill the batteries below 10V) more often than you could do that with AGM......With good 3 stage charging and de-sulfation you can keep golf cart batteries going a LONG time.
Price, Cost and value.......;-) Really the relative Amp/hours per dollar are not lower than what I have seen for Golf Cart Batteries. So if you want the most bang for your buck.....go with the golf cart. AGM's are great but VERY expensive for truly deep cycle purposes. Try pricing out a a 200 AmpHour AGM !...(not cheap).....most are much lower amphours (and even then they are only a little lighter for the real deep cycle AGM's) The upside of the AGM is as you said. They can be mounted in almost position and really no maintenance whatsover. Both will last relatively long(# of cycles).....But my gut feeling is that the Golf Cart's will take even more abuse. (kill the batteries below 10V) more often than you could do that with AGM......With good 3 stage charging and de-sulfation you can keep golf cart batteries going a LONG time.
Steve's correct
That's what I was trying to point out. Each 8D replacement requires 2 6V 225AH batteries. I'll take AGM any day for the safety, and low maintenance. With alternator and/or genset, solar and/or wind and the appropriate charge control, it would be a real bad period that anyone could kill their AGMs or golfcart batteries. AGMs just offer an additional safety factor, albeit at a price. In this P42 example, 2 8D AGM deep cycle can probably be had for about $900 with a little shopping. 4 cheapo golv cart units for about $250 including the cable mods needed, plus the additional hassle for battery box modifications. If it weren't for the box issue, I would have installed 6V AGMs. I investigated aftermarket battery boses but the P42 setup doesn't lend itself to different boxes. I would have had the maintenance and safety benefit, plus the aditional benefit of only hoisting half a battery each time as I loaded them onto the boat. BTW, each concord AGM is rated at 235AH.
That's what I was trying to point out. Each 8D replacement requires 2 6V 225AH batteries. I'll take AGM any day for the safety, and low maintenance. With alternator and/or genset, solar and/or wind and the appropriate charge control, it would be a real bad period that anyone could kill their AGMs or golfcart batteries. AGMs just offer an additional safety factor, albeit at a price. In this P42 example, 2 8D AGM deep cycle can probably be had for about $900 with a little shopping. 4 cheapo golv cart units for about $250 including the cable mods needed, plus the additional hassle for battery box modifications. If it weren't for the box issue, I would have installed 6V AGMs. I investigated aftermarket battery boses but the P42 setup doesn't lend itself to different boxes. I would have had the maintenance and safety benefit, plus the aditional benefit of only hoisting half a battery each time as I loaded them onto the boat. BTW, each concord AGM is rated at 235AH.
Why do you need a battery box?
Bill: If you go with 6V or 12V Gells or 12V AGM why do you need to worry about battery boxes at all. This is another advantage of this technology. My last battery set lasted for 10 years and I almost forgot where they were. They were Gel Cells. When they died last year, I went with AGM's. I added two more batteries to the array. I have a starting battery, a house keeping battery and 2 refrigeration batteries. None of these are in battery boxes.
Bill: If you go with 6V or 12V Gells or 12V AGM why do you need to worry about battery boxes at all. This is another advantage of this technology. My last battery set lasted for 10 years and I almost forgot where they were. They were Gel Cells. When they died last year, I went with AGM's. I added two more batteries to the array. I have a starting battery, a house keeping battery and 2 refrigeration batteries. None of these are in battery boxes.
Big Question Redux!
Have yet to see plausible reasons why major boat makers do not use golf cart batteries. The economic argument makes no sense because golf cart batteries are still cheaper wholesale than comparable Grp 24 and 27 batteries at wholesale. Disparity is even greater with 4d and 8d batteries. I believe some high end boat makers are now installing AGM batteries. There is something still missing in the arguments for golf cart batteries!
Have yet to see plausible reasons why major boat makers do not use golf cart batteries. The economic argument makes no sense because golf cart batteries are still cheaper wholesale than comparable Grp 24 and 27 batteries at wholesale. Disparity is even greater with 4d and 8d batteries. I believe some high end boat makers are now installing AGM batteries. There is something still missing in the arguments for golf cart batteries!
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