I am getting ready to up grade and replace our existing old 8+yo batteries. They have given us trouble since we bought the boat last year...constatly boiling not holding a charge ect. Currently on the boat we have 2 banks of batteries....one bank has 4- 6V Golf cart batteries run in series. the second bank has 2- 6V golf cart batteries. Unfortunatly there is no discriptors on the existing batteries..cranking amps..Amp Hours...nothing. I am replacing the engine in a few weeks and I thought this would be a good time to replace my old battery banks also. We have a heart inverter/ battery monitor My goal was to install the largest bel batteries I could...we are a cruising family sailboat,,,have refrigeration and minimal appliances that draw. My question to the group is...can I replace my existing 6- 6V batteries with 3-12 volts batteries......I have room for the 12's and Im possibly thinking of throwing a 4th battery so I would have 2 banks with 2 batteries on each at 12v. The gel batteries I am looking at are 8D AH 225each Volts 12 CCA 1265 MCA 1615 I am not an electrican so I would appriciate any and all help. thank you. rob
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Why not stay with the golf-cart batteries?
They enjoy a very good reputation for deep-cycle batteries. I replaced my two 4D's last year, and the only reason that I did not use the T-105 golf-cart batteries was that they were just a smidgeon too tall for the battery box. I've never heard a bad word about them, and they are much easier to handle than the 4/8D monsters. The two 6v golf-cart batteries have a higher capacity than a single 4D - I'm not sure about an 8D. BTW- prices vary widely - I've seen them as low as $65 each. (See the related link.) You might want to take a serious look at your charging system while you are at it - just in case that is what is causing the problem. Eight years ain't bad however
, I hope I can do that good.
They enjoy a very good reputation for deep-cycle batteries. I replaced my two 4D's last year, and the only reason that I did not use the T-105 golf-cart batteries was that they were just a smidgeon too tall for the battery box. I've never heard a bad word about them, and they are much easier to handle than the 4/8D monsters. The two 6v golf-cart batteries have a higher capacity than a single 4D - I'm not sure about an 8D. BTW- prices vary widely - I've seen them as low as $65 each. (See the related link.) You might want to take a serious look at your charging system while you are at it - just in case that is what is causing the problem. Eight years ain't bad however
, I hope I can do that good.New Batteries
You might want to find out why your batteries are boiling before replacing them. I just went through that and found the charger was only charging in the highest mode. Replaced charger and batteries. Pat
You might want to find out why your batteries are boiling before replacing them. I just went through that and found the charger was only charging in the highest mode. Replaced charger and batteries. Pat
Love my gels. .
but when I replace them it will be with AGMs. My starter battery(switch pos. #1) is a 900CCA AGM. My three house batteries are gels. They have been down in the hole and untouched for five seasons. Hoping for five more years. But AGMs are as good or better plus cheaper. I do not understand two banks of two each. Is the starter battery separate? If you have room for four house batteries just wire them all in parallel. One red wire to switch position two and another red wire to the Heart inverter/charger. I use a combiner. Once the combiner senses that the house bank is charged it "opens" to charge the starter battery. Otherwise the starter and house banks are entirely separate(except for common ground). I agree with Pat. You need to find the source of your current problem before anything else.
but when I replace them it will be with AGMs. My starter battery(switch pos. #1) is a 900CCA AGM. My three house batteries are gels. They have been down in the hole and untouched for five seasons. Hoping for five more years. But AGMs are as good or better plus cheaper. I do not understand two banks of two each. Is the starter battery separate? If you have room for four house batteries just wire them all in parallel. One red wire to switch position two and another red wire to the Heart inverter/charger. I use a combiner. Once the combiner senses that the house bank is charged it "opens" to charge the starter battery. Otherwise the starter and house banks are entirely separate(except for common ground). I agree with Pat. You need to find the source of your current problem before anything else.
Bank Organization...
You're dividing up your banks into two 225 AH banks with one 8D apiece. Most sailors today prefer a single house bank with a lot of capacity combined with a smaller single starting battery, say a group 27 or group 25. If I had two 8Ds, I'd make a single 450AH house bank (ooh baby!) and then buy a smaller, less expensive battery for the starting bank. I would go one step further and combine the two otherwise separated banks with a battery combiner so they would charge from the alternator simultaneously. I prefer to place smaller batteries in parallel to build up a house bank instead of using big batteries like the 8Ds. I get redundancy, and I don't have to hurt my back getting those 8Ds on board! For example, my house bank consists of 4 Group 27 Gels. By the way, if you choose AGMs instead of Gels, you can use a less expensive flooded battery for the starting battery, since AGMs use the same charging voltages as flooded batteries. Paul
You're dividing up your banks into two 225 AH banks with one 8D apiece. Most sailors today prefer a single house bank with a lot of capacity combined with a smaller single starting battery, say a group 27 or group 25. If I had two 8Ds, I'd make a single 450AH house bank (ooh baby!) and then buy a smaller, less expensive battery for the starting bank. I would go one step further and combine the two otherwise separated banks with a battery combiner so they would charge from the alternator simultaneously. I prefer to place smaller batteries in parallel to build up a house bank instead of using big batteries like the 8Ds. I get redundancy, and I don't have to hurt my back getting those 8Ds on board! For example, my house bank consists of 4 Group 27 Gels. By the way, if you choose AGMs instead of Gels, you can use a less expensive flooded battery for the starting battery, since AGMs use the same charging voltages as flooded batteries. Paul
Need More Ampre-Hours? Go Heavy Duty
If there is no need to change battery type (to gas-free or what ever), then the lowest cost Ampre-Hour/Cycle is the standard golf cart (in Trojans that the T-105). Not only that but as Derek mentioned, with 6-volt batteries they are easier to move about, sort of like an 8D broken in half. If the goal is to get more Ampre-hours then consider going to "Heavy Duty" golf carts at, I believe, 245 A-H. They will cost slightly more thant the T-105s probably because there are not as many of them sold but there will be more A-H in the same footprint. The age of your existing batteries is a good testimonial to what they are capable of life-span-wise. I went about the same time (9 years) on mine and the boat sits for about a half-year during the off-season which is probably harder on the batteries but I think the large charge from the Heart inverter at 50 amps helps them to keep their condition up. What I noticed before replacing my old T-105s was the voltage in a charged condition was still right up there at over 12.8 volts but they didn't seem to have the "life" that they once had so I decided to change them out anyway. Anyway, something to consider.
If there is no need to change battery type (to gas-free or what ever), then the lowest cost Ampre-Hour/Cycle is the standard golf cart (in Trojans that the T-105). Not only that but as Derek mentioned, with 6-volt batteries they are easier to move about, sort of like an 8D broken in half. If the goal is to get more Ampre-hours then consider going to "Heavy Duty" golf carts at, I believe, 245 A-H. They will cost slightly more thant the T-105s probably because there are not as many of them sold but there will be more A-H in the same footprint. The age of your existing batteries is a good testimonial to what they are capable of life-span-wise. I went about the same time (9 years) on mine and the boat sits for about a half-year during the off-season which is probably harder on the batteries but I think the large charge from the Heart inverter at 50 amps helps them to keep their condition up. What I noticed before replacing my old T-105s was the voltage in a charged condition was still right up there at over 12.8 volts but they didn't seem to have the "life" that they once had so I decided to change them out anyway. Anyway, something to consider.
I'm with Ed.
Rob: I am with Ed. I know that a lot of the sailors like to go with cheap batteries from the warehouse clubs and replace them every few years. I personally had Gels too and they lasted for 10+ yrs. I almost forgot that there where batteries on the boat. They do not need to have the terminals cleaned or water checked. I would also suggest that you take a look at the AGM's. They can also be purchased in 6V models too. We have our battery bank broken up into three banks. One for starting, one for housekeeping and the other for refrigeration. Most will recommend only two banks, but this way I figure when the refrigeration uses up it's share, I still have lights. I also would suggest that you make sure that you get a battery charger that will work with the different technologies to maximize the battery efficiency. This is good time to look at this being that you are boiling away your old batteries. It may just be that the old batteries are bad and not taking a charge.
Rob: I am with Ed. I know that a lot of the sailors like to go with cheap batteries from the warehouse clubs and replace them every few years. I personally had Gels too and they lasted for 10+ yrs. I almost forgot that there where batteries on the boat. They do not need to have the terminals cleaned or water checked. I would also suggest that you take a look at the AGM's. They can also be purchased in 6V models too. We have our battery bank broken up into three banks. One for starting, one for housekeeping and the other for refrigeration. Most will recommend only two banks, but this way I figure when the refrigeration uses up it's share, I still have lights. I also would suggest that you make sure that you get a battery charger that will work with the different technologies to maximize the battery efficiency. This is good time to look at this being that you are boiling away your old batteries. It may just be that the old batteries are bad and not taking a charge.
battery dilemma??
Rob this is just my opinon so you can take it with a grain of salt.Gel batteries are good(expensive and are sensitive to charge voltage)but require little maintence.I choose the golf cart 6 volt.The 8D's are heavy and if one cell dies you have to replace the whole battery,you indicated the 8D's have X number of CCA,usually deep cycle are rated in amp hrs.so be sure that the charge cycle is somewhere around 500 times,also i think the the 6's give more amp. hrs and are easy to obtain while cruising.Not knowing your engine HP deep cycle's do not like starting engines of higher HP.(they like to give up their amp's slow)so you might want to think about starting batt. hope this may have been help to you.
Rob this is just my opinon so you can take it with a grain of salt.Gel batteries are good(expensive and are sensitive to charge voltage)but require little maintence.I choose the golf cart 6 volt.The 8D's are heavy and if one cell dies you have to replace the whole battery,you indicated the 8D's have X number of CCA,usually deep cycle are rated in amp hrs.so be sure that the charge cycle is somewhere around 500 times,also i think the the 6's give more amp. hrs and are easy to obtain while cruising.Not knowing your engine HP deep cycle's do not like starting engines of higher HP.(they like to give up their amp's slow)so you might want to think about starting batt. hope this may have been help to you.
Split and Separate-Use Battery Banks
I'm glad that you have enjoyed years of battery life. I still, however, don't understand splitting batteries for dedicated uses, like house and refigeration. Try this: IS IT BETTER TO HAVE ONE OR TWO BATTERY BANKS FOR HOUSE USE? (By Nigel Calder - I DIDN’T write this!!!) The popular arrangement of having two house banks alternated in use needs scrutiny before I go any further. LIFE CYCLES: As we have seen, the life expectancy of a battery in cycling service is directly related to the depth to which it is discharged at each cycle - the greater the depth of discharge, the shorter the battery’s life. This relationship between depth of discharge and battery life is NOT linear. As the depth of discharge increases, a battery’s life expectancy is disproportionately shortened. A given battery may cycle through 10% of its capacity 2,000 times, 50% of its capacity 300 times and 100% of its capacity around 100 times. Let’s say, for arguments sake, that a boat has two 200-ah battery banks, alternated from day to day, with a daily load of 80 Ah. Each bank will be discharged by 40% (80 Ah of one of the two 200 Ah banks) of its capacity before being recharged. The batteries will fail after 380 cycles, which is 760 days (since each is used every other day). If the two banks had been wired in parallel, to make a single 400 Ah battery bank, this bank would have been discharged by 20% of capacity every day, with a life expectancy of 800 days, a 5% increase in life expectancy using exactly the same batteries! But now let’s double the capacity of the batteries, so that the boat has either two 400 Ah banks, or a single 800 Ah bank, but with the same 80 Ah daily load. The two separate banks will be cycling through 20% of capacity every other day, resulting in a total life expectancy of 1,600 days. Doubling the size of the battery banks in relation to the load has produced a 210% increase in life expectancy. The single 800 Ah bank will be cycling through 10% of capacity every day, resulting in a life expectancy of 2,000 days - a 25% increase in life expectancy over the two (400 Ah) banks, and a 250% increase in life expectancy over the single 400 Ah battery bank! There are two immediate conclusions to be drawn from these figures: 1. For a given total battery capacity, wiring the (house) batteries into a single high capacity bank, rather than having them divided into two alternating banks, will result in a longer overall life expectancy for the batteries. 2. All other things being equal, any increase in the overall capacity of a battery bank will produce a disproportionate increase in its life expectancy (through reducing the depth of discharge at each cycle). FOR BATTERY LONGEVITY, A SINGLE LARGE (HOUSE) BANK, THE LARGER THE BETTER, IS PREFERABLE TO DIVIDED (HOUSE) BANKS. I also agree that finding out what's making your batteries cook is the FIRST thing to do. Sounds like your charger needs some checking or replacement. Stu
I'm glad that you have enjoyed years of battery life. I still, however, don't understand splitting batteries for dedicated uses, like house and refigeration. Try this: IS IT BETTER TO HAVE ONE OR TWO BATTERY BANKS FOR HOUSE USE? (By Nigel Calder - I DIDN’T write this!!!) The popular arrangement of having two house banks alternated in use needs scrutiny before I go any further. LIFE CYCLES: As we have seen, the life expectancy of a battery in cycling service is directly related to the depth to which it is discharged at each cycle - the greater the depth of discharge, the shorter the battery’s life. This relationship between depth of discharge and battery life is NOT linear. As the depth of discharge increases, a battery’s life expectancy is disproportionately shortened. A given battery may cycle through 10% of its capacity 2,000 times, 50% of its capacity 300 times and 100% of its capacity around 100 times. Let’s say, for arguments sake, that a boat has two 200-ah battery banks, alternated from day to day, with a daily load of 80 Ah. Each bank will be discharged by 40% (80 Ah of one of the two 200 Ah banks) of its capacity before being recharged. The batteries will fail after 380 cycles, which is 760 days (since each is used every other day). If the two banks had been wired in parallel, to make a single 400 Ah battery bank, this bank would have been discharged by 20% of capacity every day, with a life expectancy of 800 days, a 5% increase in life expectancy using exactly the same batteries! But now let’s double the capacity of the batteries, so that the boat has either two 400 Ah banks, or a single 800 Ah bank, but with the same 80 Ah daily load. The two separate banks will be cycling through 20% of capacity every other day, resulting in a total life expectancy of 1,600 days. Doubling the size of the battery banks in relation to the load has produced a 210% increase in life expectancy. The single 800 Ah bank will be cycling through 10% of capacity every day, resulting in a life expectancy of 2,000 days - a 25% increase in life expectancy over the two (400 Ah) banks, and a 250% increase in life expectancy over the single 400 Ah battery bank! There are two immediate conclusions to be drawn from these figures: 1. For a given total battery capacity, wiring the (house) batteries into a single high capacity bank, rather than having them divided into two alternating banks, will result in a longer overall life expectancy for the batteries. 2. All other things being equal, any increase in the overall capacity of a battery bank will produce a disproportionate increase in its life expectancy (through reducing the depth of discharge at each cycle). FOR BATTERY LONGEVITY, A SINGLE LARGE (HOUSE) BANK, THE LARGER THE BETTER, IS PREFERABLE TO DIVIDED (HOUSE) BANKS. I also agree that finding out what's making your batteries cook is the FIRST thing to do. Sounds like your charger needs some checking or replacement. Stu
"Car" Battery Better For Starting
Darrel's comment about the start battery is right on. Test it yourself sometime. The next time you go to replace your car battery try it out on the boat first and see how it spins your engine. Heck, even take the car battery you're going to return for the deposit and try it out. Think you'll be more than a little surprized. And it doesn't have to be a big battery, either! Even an old Honda Civic battery will do.
Darrel's comment about the start battery is right on. Test it yourself sometime. The next time you go to replace your car battery try it out on the boat first and see how it spins your engine. Heck, even take the car battery you're going to return for the deposit and try it out. Think you'll be more than a little surprized. And it doesn't have to be a big battery, either! Even an old Honda Civic battery will do.
Thank you everyone
Well,,,,,I think I am just as confused as when i started......One agreement is I will check my charger and find out why my batteries are bubbling over. The bank that is the culpret is connected to my refrigeration......I notice that when my refrigeration kicks on my batteries drain the most Im constantly adding water to those batteries....the other time is when Im hooked to shore power. Now as to switching battery types.......our batteries are seperated into 2 banks. 1 as a house bank with 4- 6v batteries and 1 as a starting bank as 2- 6v.............Im still torn as to what to replace them with. My first question is can you replace 2- 6v with 1- 12volt?..it makes sense to me....as long as the cranking amps and AH are higher. The second is I want to add as much AH to my house bank as possible,,scince my 2 kids, wife and I use things like stereo, shower (pumps), tv, blender, lights ect when out at anchor...and am trying to minimize charging cycles with engine on. As I mentioned we are replacing my tiered 20yo siezed Perkins 4-108 with a new Volvo D2-55 and will have a mechanic and electrician on the boat for this installation...I thought it would be a good time to solve this charging problem and battery replacement. Any thoughts as to 2-6volts vs 1-12 and AH at house banks? Thanks Rob
Well,,,,,I think I am just as confused as when i started......One agreement is I will check my charger and find out why my batteries are bubbling over. The bank that is the culpret is connected to my refrigeration......I notice that when my refrigeration kicks on my batteries drain the most Im constantly adding water to those batteries....the other time is when Im hooked to shore power. Now as to switching battery types.......our batteries are seperated into 2 banks. 1 as a house bank with 4- 6v batteries and 1 as a starting bank as 2- 6v.............Im still torn as to what to replace them with. My first question is can you replace 2- 6v with 1- 12volt?..it makes sense to me....as long as the cranking amps and AH are higher. The second is I want to add as much AH to my house bank as possible,,scince my 2 kids, wife and I use things like stereo, shower (pumps), tv, blender, lights ect when out at anchor...and am trying to minimize charging cycles with engine on. As I mentioned we are replacing my tiered 20yo siezed Perkins 4-108 with a new Volvo D2-55 and will have a mechanic and electrician on the boat for this installation...I thought it would be a good time to solve this charging problem and battery replacement. Any thoughts as to 2-6volts vs 1-12 and AH at house banks? Thanks Rob
6 volt golf carts
6 volt golf cart batteries will give you more amp hours than a 12 volt deep cycle. For your house bank, 6 volt would be better. Your starting battery could be a 12 volt marine starting type and would be just fine.
6 volt golf cart batteries will give you more amp hours than a 12 volt deep cycle. For your house bank, 6 volt would be better. Your starting battery could be a 12 volt marine starting type and would be just fine.
Lifeline AGM batteries
I can't comment on your current battery config, but offer some thoughts. I recently replaced my 2 year old "ProMariner" charger on my 2001 C-36, when it decided to fry my batteries. (The same model was guilty of the same crime with several of my neighbors' boats) I researched batteries, and had even ordered West Marine's AGM batteries (2 4D's). Then, I continued my research, and found that no battery reviewed as well as Lifeline AGM batteries. Additionally, they were available locally, and for less than WM's inferior version. I cancelled my WM order, and got the Lifelines. I couldn't be happier (except for the $700 hole in my wallet).
I can't comment on your current battery config, but offer some thoughts. I recently replaced my 2 year old "ProMariner" charger on my 2001 C-36, when it decided to fry my batteries. (The same model was guilty of the same crime with several of my neighbors' boats) I researched batteries, and had even ordered West Marine's AGM batteries (2 4D's). Then, I continued my research, and found that no battery reviewed as well as Lifeline AGM batteries. Additionally, they were available locally, and for less than WM's inferior version. I cancelled my WM order, and got the Lifelines. I couldn't be happier (except for the $700 hole in my wallet).
Stu and Nigel are right
Having been an engineer and electrician for over twenty years and having read quite a bit of Nigels work, I have always found his advice to be based on sound engineering principals. His advice on this subject is also correct. To make it simple...go with one LARGE house bank, have a seperate battery for starting, use a battery combiner, use Lifeline AGMs (they ARE the best)if you can afford them and golf cart batteries if you can't, (BTW, AGMs are fine for starting purposes) and check the output voltage of your charger and alternator on a regular basis, as they do go bad on occasion and can ruin your batteries in short order. Hope this helps you out, Jeff S/V Katrina Marie
Having been an engineer and electrician for over twenty years and having read quite a bit of Nigels work, I have always found his advice to be based on sound engineering principals. His advice on this subject is also correct. To make it simple...go with one LARGE house bank, have a seperate battery for starting, use a battery combiner, use Lifeline AGMs (they ARE the best)if you can afford them and golf cart batteries if you can't, (BTW, AGMs are fine for starting purposes) and check the output voltage of your charger and alternator on a regular basis, as they do go bad on occasion and can ruin your batteries in short order. Hope this helps you out, Jeff S/V Katrina Marie
Good advice here,,,,
and we don't even use a start battery. Just one bank of golf carts. It is much simpler than two banks and works great. If we ever would kill the only bank, we would just release the compression levers to start the engine. But that hasn't happened in 15 years.
and we don't even use a start battery. Just one bank of golf carts. It is much simpler than two banks and works great. If we ever would kill the only bank, we would just release the compression levers to start the engine. But that hasn't happened in 15 years.
Maybe not such good advice there....
When's the last time anyone just "released the compression levers" on a diesel and hand-cranked it? I'd love to hear from anyone who has ever hand-started a 3GMF30 or similar-sized diesel. Have a starting battery.
When's the last time anyone just "released the compression levers" on a diesel and hand-cranked it? I'd love to hear from anyone who has ever hand-started a 3GMF30 or similar-sized diesel. Have a starting battery.
Paul, No, No, No
I didn't say HAND CRANK IT! Read your Yanmar owners manual. My 3GM30F manual refers to the compression release levers as the 'low battery, start levers'. Just open 'em and hit the start button. When the engine spins up, close one of them. Then the others. Man, you gotta really be dead for that not to work! All of your electronics would have stopped working. It's never happened to us. Anybody out there tried this with a dead battery and NOT have it work?
I didn't say HAND CRANK IT! Read your Yanmar owners manual. My 3GM30F manual refers to the compression release levers as the 'low battery, start levers'. Just open 'em and hit the start button. When the engine spins up, close one of them. Then the others. Man, you gotta really be dead for that not to work! All of your electronics would have stopped working. It's never happened to us. Anybody out there tried this with a dead battery and NOT have it work?
Fred, never tried it but,
that is exactly what my mechanic told me to do in case of a low battery.
that is exactly what my mechanic told me to do in case of a low battery.
Boat Electrical Systems
Harry I'm guessing that Pat figured it out by monitoring the output voltage of the charger. ************************* ************************* Rob, The link is to the C34 website, with a Find on the message board for C34 Electrical Systems. Rather than repeating a lot of what has already been written, I recommend that you look through these references and posts. They address many issues of concern about electrical systems that have been brought up on this and other sites. A particular link that is right up your alley, Rob, is [in addition to the related link]: http://c34.infopop.cc/6/ubb.x?a=tpc&s=329609511&f=829605811&m=654602911&r=164602911#164602911 Electrical systems are based on how YOU use your boat. There is NO ONE RIGHT ANSWER that suits everybody. All the best, and happy reading. Stu
Harry I'm guessing that Pat figured it out by monitoring the output voltage of the charger. ************************* ************************* Rob, The link is to the C34 website, with a Find on the message board for C34 Electrical Systems. Rather than repeating a lot of what has already been written, I recommend that you look through these references and posts. They address many issues of concern about electrical systems that have been brought up on this and other sites. A particular link that is right up your alley, Rob, is [in addition to the related link]: http://c34.infopop.cc/6/ubb.x?a=tpc&s=329609511&f=829605811&m=654602911&r=164602911#164602911 Electrical systems are based on how YOU use your boat. There is NO ONE RIGHT ANSWER that suits everybody. All the best, and happy reading. Stu
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