3 bank battery charger. How many amps needed?

88dancer300

New Member
Feb 14, 2010
653
new england coast
Boat Info
1988 Sundancer 300, Heat/AC,gennie,central vac,Ice maker stretched swim platform, monster stereo sys
Engines
Twin 5.7 liter 260hp closed cooling system Mercruisers with Alpha one drives.
:huh:Good morning. I am thinking on replaceng my old orig. battery charger. I run 3 group 31 batteries, and am wondering how many amp charger I really need? I have a 35 amp now, so its a little less than 13 amps per bank. but do I really need all that? I have kind of a tight budget. I see them anywhere from 13 -40 total amps. I use the boat only on the weekends, so it has all week to charge, twin 5.7s and have a Westerbeke 4kw gennie, just dont know what will fit my needs. Thanx.
 
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I use a 30 amp but note that some chargers rated at 30A put out 30 per bank and some put out out 10 per bank. My charger monitors each bank separately and then adjusts charge per requirements. I have two 2 battery banks and one gen battery so I use all three outputs.
 
:huh:Good morning. I am thinking on replaceng my old orig. battery charger. I run 3 group 31 batteries, and am wondering how many amp charger I really need? I have a 35 amp now, so its a little less than 13 amps per bank. but do I really need all that? I have kind of a tight budget. I see them anywhere from 13 -40 total amps. I use the boat only on the weekends, so it has all week to charge, twin 5.7s and have a Westerbeke 4kw gennie, just dont know what will fit my needs. Thanx.
I'm looking at doing the same thing. It looks like our boats are pretty similar, I have the same genset and accessories you have. I have an electrician scheduled to come Monday and I will let you know what he recommends.
 
I have a 40A Promariner "Pronautic 1240Ci" It's a 3 bank charger with digital display. What do you have now?
 
My Charles smart charger is rated at 20 AMPS.
It pegs the meter when the 3 batterys are low. Then it will go into a trickle charge.
Charles states that there 20 AMP charger will keep up with 2000 Watts DC draw when plugged in
to the boats shore power. Nice when theres a little Genny on board.

With that said....
There 10 AMP charger good for 1000 Watts DC draw?
There 30 AMP Charger good for 3000 Watts DC draw?
A lower AMP charger just takes longer to fully charge the battery's.
The charger also gives the batterys a boost for starting when plugged in, and added AMPs
for charging if the batterys are in poor shape.
 
I just ran into this. Make sure you get the right charger. I had a Promariner Pro-sport and the company told me it was the wrong charger as it was not designed for a constant draw such as bilge pump, cabin lights etc. They recommened the Pronautic 1240Ci that Todd has suggested above.
 
Great, thanx. I will also look into the Pronautic 1240ci.
I'm looking at doing the same thing. It looks like our boats are pretty similar, I have the same genset and accessories you have. I have an electrician scheduled to come Monday and I will let you know what he recommends.
 
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Seems the chargers need the power to keep up with your DC power draw while on the hook or slip.
 
I have the small 6 amp Pro-Mariner charger hooked to one battery, when I want to charge both batteries, I set the main battery switch to "All" and it trickle charges both batteries. In about 2-3 hours the red light goes out and it is in "maintenance mode" where it just keeps the batteries up. I've done this on both boats I've owned for years now and it works just fine for anything I've run on the boat. A 35 or 40 amper is for running big 12v stuff all the time and not wanting to pull anything out of your batteries. That is a pretty rare occurrence.
 
I also went with the pronautic 1240. I'm running three group 31 die hard agm platinums. So far so good!
 
I found this charger. Its an onboard 4 bank 40 amp 12-48v waterproof. Its a (NOCO GENIUS Gen 4) Found it at Sportsman Guide. It has great reviews, made in the U.S. and comes with a 3 year warranty. $299.97
 
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Dave I must have got you thinking about a charging system for your boat.

Here is what I have for my boat; A Xantrex Freedom Marine Charger 1000 with a built in 1000 watt inverter. The charger is 50 amps with a 13 amp echo charger for the starting battery. I also have a link 1000 which controls the entire system. For batteries I have a Interstate starting battery I forget the size but it is what they recommend to start a 350 Chev Marine engine, I have 2 Interstate Golf Cart batteries for my house batteries 225 amps.
I must tell you this system is not cheap, the charger was about $650.00 and the link was around $275.00 say it quick and it does not hurt.
This gives me 225 amp hours while on the hook, wrong, you can only use about 1/2 the amps of the system so I have about 120 amp hours that I can use while on the hook.
When we are anchored out we draw about 10 amp hours on average, the electric head draws 45 amps when you push that button, don't be pushing it for very long. We get about 14 hours before we have to recharge. This is where your charger now needs to do a good job, mine is 50 amps but in reality the charger only puts out about 43 or 45 amp hours. This is where you need to do some math, the batteries are down 120 amp hours so it is going to take 3 hours to charge the batteries, wrong, a smart charger reads the batteries and it even takes the temperature of the batteries into consideration, the charge will drop off after 1/2 hour down to 35 to 39 amps and then down to the 25 to 30 amp hours after about an hour. It won't over heat your batteries which causes gassing and evaporation of the water.
I don't know if this type of system is right for you but we anchor out a lot and a good charging system is a must.
We only use the inverter to power the lap top when under way or to recharge it when anchored.

Ken
 
.....That is a pretty rare occurrence.
Not for me. If I'm the hook, using the water pump, vacuflush, lights, refer, etc, it will take the house down in a day(with the existing set up GRP27 for the house~switching to 2-6Vs for the house). When I get back to a marina with shorepower it's nice to have the power of this charger to rapidly replenish my house batts. A 6A charger will take a day or longer to recharge. It's just too smalll for a small cruiser in my opinion.

Spend a little extra for a decent charger and make that a component of your boating you won't have to think about or wait for all the time.
Best of luck.
 
Wow, thats quite a charging syst. I think overkill for me. I think I will look for a good quality 40 amp. 4 bank charger.
 
Well after a lot of research of different products, I am going to need a 4 bank smart charger with a fast recovery time. I am away from my slip every weekend on the hook in a large raft up. My fridge runs all weekend (only keep meats in it, and only open to get at it), The Vacuflush system a few times a day, lights at night (most LED), We run the windlass frequently throughout the weekend for adjusting to keep us right on the beach (Ocean tide change), Water pump does not run much, but my big problem is the 80 amps that my stereo pulls when is flat out while partying at night (3 amplifiers 1900 watts, four 8" coaxials, and a 12" R series competition subwoofer.) Our boat is the entertainment for the raft. Looks like the Promariner tournament 300 quad might do fine. Its a 3 step smart charger that will deliver 30 amps to any low battery at any time, with a recovery time of 3-5 hours. Example: if I have drained one of my 4 group 31s with the stereo syst., and the other 3 are fully charged, all of the chargers available amperage will be directed to that one low battery, and when its topped off, the charger will go back to maintaining all 4 banks. Im open to any other suggestions, as this is my first venture into the battery charger world. Thanx.
 
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:smt001Update: I just spoke with pro nautic, and they informed me that the tournament 300 quad is not right for a cruiser, it is designed for a bass boat. and the load that will be put on it, will cook it in 2 weeks. He recommended the pronautic 1260P 3 bank 60 amp charger. He can give it to me for $470.00 and it is in stock. If anyone is intrested in talking to him about your needs, give him a call. The technicians name is Brian and his # is 603-438-4440. They are located in Rye N.H. Very helpfull.
 
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:smt001Update: I just spoke with pro nautic, and they informed me that the tournament 300 quad is not right for a cruiser, it is designed for a bass boat. and the load that will be put on it, will cook it in 2 weeks. He recommended the pronautic 1260 3 bank 60 amp charger. He can give it to me for $470.00 and it is in stock. If anyone is intrested in talking to him about your needs, give him a call. The technicians name is Brian and his # is 603-438-4440. They are located in Rye N.H. Very helpfull.

Sounds familiar.........
 
:smt001Update: I just spoke with pro nautic, and they informed me that the tournament 300 quad is not right for a cruiser, it is designed for a bass boat. and the load that will be put on it, will cook it in 2 weeks. He recommended the pronautic 1260 3 bank 60 amp charger. He can give it to me for $470.00 and it is in stock. If anyone is intrested in talking to him about your needs, give him a call. The technicians name is Brian and his # is 603-438-4440. They are located in Rye N.H. Very helpfull.

Sounds familiar.........

Yep. They are great to work with. Get the optional remote too.
FinalChargerinstall5-4-088.jpg

FinalChargerinstall5-4-087.jpg
 

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