Add a 3rd Battery
- Thread starter Ron M
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My B361 has 2 4D batteries for the house and 1 group 27 for the starter. Only down side I see is the physical size and weight of the 4D batteries. I'm not sure how long they will last (they are 2 years old now), but when they are done, I will definitely look for something with the same amount of power but also something easier to handle.
Battery expectations
My B361 also had two 4ds (in parallel) and a group 27 starting battery. The 4ds are lead acid and have about 400 amp hours of total power. I've never been able to exhaust them. They will last about 5 years with proper care.
If you really want some serious battery capacity, you won't get it from "car sized" batteries (Group 24 or 27). You will need 4ds or 8ds. Yes, they are heavy, but when placed near the keel the weight has a benefit.
Agaliha
My B361 also had two 4ds (in parallel) and a group 27 starting battery. The 4ds are lead acid and have about 400 amp hours of total power. I've never been able to exhaust them. They will last about 5 years with proper care.
If you really want some serious battery capacity, you won't get it from "car sized" batteries (Group 24 or 27). You will need 4ds or 8ds. Yes, they are heavy, but when placed near the keel the weight has a benefit.
Agaliha
ProfRon:
I added a third battery to my 331. it was easy. The refigeration does not draw the batteries down overnight now, and it seems that I do not have the boil-off of water that I had with two batteries. If you will provide me with your email address or call me I will scan the data and send it to you.
I added a third battery to my 331. it was easy. The refigeration does not draw the batteries down overnight now, and it seems that I do not have the boil-off of water that I had with two batteries. If you will provide me with your email address or call me I will scan the data and send it to you.
There are several experts on electricity out there...
One group 27 is definitely not enough unless you are are either on the grid or motoring all the time.
I have four (4) 225 Amp 6V, which gives me a bit more than 110 usable Amps. I can run the refrigerator and Webasto heating all night and still have enough for the morning net on the SSB.
Since I'm on a mooring I have two 85 Amp solar panels; I leave the fridge and anchor light on all the time and the batteries do not go down... The well regulated system doesn't boil up either: I haven't added water in the batteries for the last two years.
The 6V batteries weigh less than a 4D and take up about the same space. I have two of them in a 4D box and the other two in group 27 boxes because of space considerations.
I also changed the alternator for a 70 Amp Balmar with external regulator. A mooring is nice but free electricity isn't cheap!
Pierre le Caboteur
One group 27 is definitely not enough unless you are are either on the grid or motoring all the time.
I have four (4) 225 Amp 6V, which gives me a bit more than 110 usable Amps. I can run the refrigerator and Webasto heating all night and still have enough for the morning net on the SSB.
Since I'm on a mooring I have two 85 Amp solar panels; I leave the fridge and anchor light on all the time and the batteries do not go down... The well regulated system doesn't boil up either: I haven't added water in the batteries for the last two years.
The 6V batteries weigh less than a 4D and take up about the same space. I have two of them in a 4D box and the other two in group 27 boxes because of space considerations.
I also changed the alternator for a 70 Amp Balmar with external regulator. A mooring is nice but free electricity isn't cheap!
Pierre le Caboteur
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Where batteries
Hi, ProfRon
Two are in front on the engine under the stairs: they had to be installed in gp27 cases, side by side. The other two are set against the forward end of the storage area; they are set end to end in a 4D or 8D storage box. There is a little recessed area there and I put my inflatable life-jackets over this.
I left the starter battery, 110V charger and battery insulator in place.
I should go to the boat during the week, I can post pics of all this if you wish. I can't do it this weekend because we are babysitting the grand-daughters (3). The 31 is certainly a little different from the 331 but I got the plan for the solar panels from someone here with a 331... and I think she has a total of five batteries as well.
I might have overdone the electricity a little but we are going to the Bahamas this fall and might take some moorings once in awhile but the rest will be on the hook and staying in one spot several days at a time... We take the better part of four months to make that trip, that is just to make it to Bimini, then we slow down!
Pierre le Caboteur
Hi, ProfRon
Two are in front on the engine under the stairs: they had to be installed in gp27 cases, side by side. The other two are set against the forward end of the storage area; they are set end to end in a 4D or 8D storage box. There is a little recessed area there and I put my inflatable life-jackets over this.
I left the starter battery, 110V charger and battery insulator in place.
I should go to the boat during the week, I can post pics of all this if you wish. I can't do it this weekend because we are babysitting the grand-daughters (3). The 31 is certainly a little different from the 331 but I got the plan for the solar panels from someone here with a 331... and I think she has a total of five batteries as well.
I might have overdone the electricity a little but we are going to the Bahamas this fall and might take some moorings once in awhile but the rest will be on the hook and staying in one spot several days at a time... We take the better part of four months to make that trip, that is just to make it to Bimini, then we slow down!
Pierre le Caboteur
Pierre,
Photos would be wonderful. This is not an immediate project so any time would be fine. Are your 4 house batteries just wired in parallel? I contacted the local Beneteau dealer and he suggested the best approach would be to rewire the boat to include new battery switches, alternator, charger, etc (way beyond what I want to do). But he also admitted that most owners simply add a battery in parallel with the existing one.
Ron
Photos would be wonderful. This is not an immediate project so any time would be fine. Are your 4 house batteries just wired in parallel? I contacted the local Beneteau dealer and he suggested the best approach would be to rewire the boat to include new battery switches, alternator, charger, etc (way beyond what I want to do). But he also admitted that most owners simply add a battery in parallel with the existing one.
Ron
Another battery
Ron,
You can't add a new battery to an old one in a parallell bank; they won't charge well & they will discharge unevenly.
Before doing anything, try to estimate your daily demand in electricity. Refrigeration is the big item here. Is your fridge top-loading or front opening? Is the opening well gasketed? What percentage of the time is the compressor working & how much does it draw? Secondary items will be films on the computer or the TV if you have one. An incadescent anchor light draws as much as 1.5Amp for 10 hours every night you use it! If you get a little megalight drawing 0.07 Amp you could reduce your ideal battery bank by 60 Amps! Once you have added all this up you can better see what you will need for batteries & charging.
The other consideration is how you use your boat: is it mostly sitting in a marina and plugged to the grid? Do you use it mostly weekends and a two week cruise a year? If so you will compromise from the ideal solution to a practical and usable solution: ideally you should have a battery capacity that is 4 times your daily usage and your alternator should be 20% of that capacity. In absolute terms, if you use 100Amp/hrs/day you should have 400Amp/hours of battery reserve and a 80Amp externally regulated alternator.
Now, that is ideal; with a boat that doesn't get plugged in regularly. If you are plugged in your batteries get charged to 100% instead of the 75% your engine and small 35 or 60 amp. internally regulated alternator will achieve. This reduces the total needed capacity. These small alternators only produce the rated output when cold so it is more efficient to run them in small bursts... half hour at night & half hour in the morning is much more efficient than an hour in the morning.
Should you decide to add a battery, since you can't use new & old together why not get two 6V deep discharge & wire them in series. Since the 6V only have three cells they are better for deep discharge: the plates can be thicker etc.
More later... Nigel Calder's electrical etc makes fantastic reading before going into all this expense.
Pierre
Ron,
You can't add a new battery to an old one in a parallell bank; they won't charge well & they will discharge unevenly.
Before doing anything, try to estimate your daily demand in electricity. Refrigeration is the big item here. Is your fridge top-loading or front opening? Is the opening well gasketed? What percentage of the time is the compressor working & how much does it draw? Secondary items will be films on the computer or the TV if you have one. An incadescent anchor light draws as much as 1.5Amp for 10 hours every night you use it! If you get a little megalight drawing 0.07 Amp you could reduce your ideal battery bank by 60 Amps! Once you have added all this up you can better see what you will need for batteries & charging.
The other consideration is how you use your boat: is it mostly sitting in a marina and plugged to the grid? Do you use it mostly weekends and a two week cruise a year? If so you will compromise from the ideal solution to a practical and usable solution: ideally you should have a battery capacity that is 4 times your daily usage and your alternator should be 20% of that capacity. In absolute terms, if you use 100Amp/hrs/day you should have 400Amp/hours of battery reserve and a 80Amp externally regulated alternator.
Now, that is ideal; with a boat that doesn't get plugged in regularly. If you are plugged in your batteries get charged to 100% instead of the 75% your engine and small 35 or 60 amp. internally regulated alternator will achieve. This reduces the total needed capacity. These small alternators only produce the rated output when cold so it is more efficient to run them in small bursts... half hour at night & half hour in the morning is much more efficient than an hour in the morning.
Should you decide to add a battery, since you can't use new & old together why not get two 6V deep discharge & wire them in series. Since the 6V only have three cells they are better for deep discharge: the plates can be thicker etc.
More later... Nigel Calder's electrical etc makes fantastic reading before going into all this expense.
Pierre
Hi Ron & Ron,
As stated before, it's all in what you wish to do with the boat... Mine is on a mooring at our cottage and theoretically is a daysailor! It doesn't work out that way: this boat is a 2009 and I already have 2,000NM on the log! With my last boat I averaged close to 3,000NM/year for ten years, most of it at sea. You would usually consider the way I equipped this 31 foot boat as overkill. We will however leave for the Bahamas at the end of August & make our way to either the Jumentos or Turks & Caicos! and back for the end of June... that's a long time on a small boat so we want it to be comfy.
Here are the pics of: 1- 12V at the helm for low amp anchor light 2- Permanently mounted spring line (the boat has no center cleat) 3- Fender bags near the shrouds (I can then have folding bikes in the cockpit) 4- Washdown hose in the anchor well; the intake is under the galley sink & pump in the port locker beside the freshwater system 5- A box with 2 6V 225Amp/hr batteries in the cockpit locker 6- One of two grab handles in the companionway 7- Replacing the little bars on the shelves with plexi to hold whatever 8- The switching system: Starting, ground, battery bank 1, bank 2, the switch for the deck hose-down, the breaker for the anchor windlass, the round selector is for the solar system 9- The other two 225Amp 6V batteries 10- The Balmar & regulator 11- The starter battery, the original charger, a switch to put all batteries on the starting circuit.
I stopped in case you get bored... there is more!
Pierre le Caboteur
As stated before, it's all in what you wish to do with the boat... Mine is on a mooring at our cottage and theoretically is a daysailor! It doesn't work out that way: this boat is a 2009 and I already have 2,000NM on the log! With my last boat I averaged close to 3,000NM/year for ten years, most of it at sea. You would usually consider the way I equipped this 31 foot boat as overkill. We will however leave for the Bahamas at the end of August & make our way to either the Jumentos or Turks & Caicos! and back for the end of June... that's a long time on a small boat so we want it to be comfy.
Here are the pics of: 1- 12V at the helm for low amp anchor light 2- Permanently mounted spring line (the boat has no center cleat) 3- Fender bags near the shrouds (I can then have folding bikes in the cockpit) 4- Washdown hose in the anchor well; the intake is under the galley sink & pump in the port locker beside the freshwater system 5- A box with 2 6V 225Amp/hr batteries in the cockpit locker 6- One of two grab handles in the companionway 7- Replacing the little bars on the shelves with plexi to hold whatever 8- The switching system: Starting, ground, battery bank 1, bank 2, the switch for the deck hose-down, the breaker for the anchor windlass, the round selector is for the solar system 9- The other two 225Amp 6V batteries 10- The Balmar & regulator 11- The starter battery, the original charger, a switch to put all batteries on the starting circuit.
I stopped in case you get bored... there is more!
Pierre le Caboteur
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I removed the two group 24 batteries and replaced them with two trogen T 125 golf cart batteries in the engine compartment and one group 27 battery for back up startng. I have two 85 watt solar panels tied to the golf cart batteries thru a Xantrax regulator
I used led lighting including the anchor light,a stock refrigerator at 2.2 amps and an Engle Freezer at 2.5 amps
I rarely used the group 27 deep cycle battery on my 7 month cruise to the Keys and the Bahamas
I also carried a Honda 2000 generator if I chose to use any appliances that were not propane or 12 volt.
Its the size of a sewing machine and gives you that secure feeling of backup!
I used led lighting including the anchor light,a stock refrigerator at 2.2 amps and an Engle Freezer at 2.5 amps
I rarely used the group 27 deep cycle battery on my 7 month cruise to the Keys and the Bahamas
I also carried a Honda 2000 generator if I chose to use any appliances that were not propane or 12 volt.
Its the size of a sewing machine and gives you that secure feeling of backup!
PRon, I went from Back Creek over to Whitehall Bay/Creek for the weekend. I have 2, size 31, house batteries plus a 24 'engine' battery. We ran the interior LED lights as needed, ran the fans all night, but as usual I shut the fridge off at bedtime and back on when someone gets up. I have no way of knowing if two 27's would last, but the 31s have served me well- including a recent 16-day DelMarVa circumnavigation with 4 people on the 323. I have a Honda 2000 in the lazzarette which I have not had needed in the year I've owned it.
Ron,
2-31's for house bank is the direction that I'm leaning. Also, considered a single 4D. We've only owned the boat for 2 months so as a test we spent an evening in Annapolis, didn't try to be to cautious on power usage and left refer on.... house battery dead in the morning. Did you install the second house battery? Just parallel with the first? Any changes in battery charger or alternator?
2-31's for house bank is the direction that I'm leaning. Also, considered a single 4D. We've only owned the boat for 2 months so as a test we spent an evening in Annapolis, didn't try to be to cautious on power usage and left refer on.... house battery dead in the morning. Did you install the second house battery? Just parallel with the first? Any changes in battery charger or alternator?
I added a third battery to my 323 and wired in a new factory battery switch with it. 3 batteries, 3 switches. My Truecharge20/40 has outputs for 3 batteries, which really made the task somple. That way, you can turn off/on ANY combination of batteries. Not to mention being able to isolate any defective battery.
Two 31's for house bank
Hi Rons,
Were I not on a mooring, I would probably go for the two group 31's. This leaves most options open for switching on or off & isolating. For all sorts of reasons (gasolene, weight, smell, noise etc). I wouldn't go for the small generator: for occasionnal usage the main engine will do the job of recharging the batteries without the extra weight & encumbering of the mini genset.
It's the regular usage of the main engine as a genset that will eventually damage it, not the occasionnal use.
Pierre
Hi Rons,
Were I not on a mooring, I would probably go for the two group 31's. This leaves most options open for switching on or off & isolating. For all sorts of reasons (gasolene, weight, smell, noise etc). I wouldn't go for the small generator: for occasionnal usage the main engine will do the job of recharging the batteries without the extra weight & encumbering of the mini genset.
It's the regular usage of the main engine as a genset that will eventually damage it, not the occasionnal use.
Pierre
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