New battery charger..how many amps?

[Scot McPherson]

The Gen 3 chargers manage and charge each set of leads independently. They don't need external management.

[Scot McPherson]

Maine Sail, I never said ProMariner recommended a ProSport for 450 Ah. I said I have 2x 160s or 320 Ah. That's quite a step down.

[Maine Sail]

Originally Posted by Scot McPherson

Maine Sail, I never said ProMariner recommended a ProSport for 450 Ah. I said I have 2x 160s or 320 Ah. That's quite a step down.

I was just surprised you got that answer from ProMariner for your bank. ProMariner is very clear these chargers are not intended for 4D, 8D or large banks.

Originally Posted by Scot McPherson

The Gen 3 chargers manage and charge each set of leads independently. They don't need external management.

Because the ProSport charger can be used for 12V, 24V and 36V banks each set of leads needs to be connected to a 12V battery. The charger still has one charge profile & all batteries get the same absorption duration & transition profile as the others. It also has just one voltage regulation circuit meaning all batteries share the same voltage at what ever SOC & terminal voltage the lowest connected battery is at, or stage, absorption, float or pulse, the battery charger is in.

ProMariners "distributed by demand" is really not much more than essentially branding Ohm's law.... It you take a bench top power supply, that has one output and one voltage regulation circuit, and feed it through two diodes to two batteries the current will flow to the battery with the lowest resistance at XX.XX volts. This is no different than the "distributed by demand" marketing PM uses.. The marketing guys are just making it sound fancier than it really is...

ProMariner likes to compare these charger to chargers from yesteryear that used an auto-former that had two winding's & one voltage regulation circuit.. One winding per battery or 5A to each output for a 10A charger.

On an older tech charger, such as many of the inexpensive Guest models, if battery 1 was near full or could only accept .5 amps at 13.3V volts the other 4.5A went wasted. By putting a single output power supply behind some FET's or diodes we now have "distributed by demand" or the appearance the charger is doing something much fancier & more complex than it really is.

[barnakiel]

I have installed a 100A unit into a 440Ah boat recently. I like the charger to be about 25% of the capacity (much as this is very hard to attain in any bigger boat). This is a boat that cruises and they have shore power only now and then (say 2 times a week or less often).

We have a 25A unit in a 110Ah boat ourselves. (We are a 99% 'solar' boat).

I think if you tend to spend long periods at the dock (overnights, or full days), you can have just a very wee charger, say 20A, as all this one has to do is keep the balance in a 24 hour cycle.

Take you daily consumption then, divide by 24, add a small margin, and that's that. You only need to put in what you take out, and a small margin, to keep the bank happy and last.

b.

[Luther]

Thanks to you all.
I've ordered the ProMariner 30amp....

[wingless]

The Lifeline Technical Manual is THE BEST resource I've found for AGM batteries.

They state that AGM batteries should be charged as fast as practical, that an AGM battery should be bulk charged at up to the 5C rate. That is, for a 100Ah battery, the bulk charge rate should be up to 500A.

[btrayfors]

Originally Posted by barnakiel

I have installed a 100A unit into a 440Ah boat recently. I like the charger to be about 25% of the capacity (much as this is very hard to attain in any bigger boat). This is a boat that cruises and they have shore power only now and then (say 2 times a week or less often).

We have a 25A unit in a 110Ah boat ourselves. (We are a 99% 'solar' boat).

I think if you tend to spend long periods at the dock (overnights, or full days), you can have just a very wee charger, say 20A, as all this one has to do is keep the balance in a 24 hour cycle.

Take you daily consumption then, divide by 24, add a small margin, and that's that. You only need to put in what you take out, and a small margin, to keep the bank happy and last.

b.

Bingo! All this learned talk, and nobody mentions the most important consideration....except you!

Yes, the choice of a battery charger -- in addition to battery type and capacity -- should consider the type of cruising to be done. If you're at dockside and plugged in most of the time, a smaller capacity charger will do just fine. If you only occasionally plug in, -- or if you count on a generator to provide the AC to power a battery charger -- then you want a large capacity charger.

How large? The largest you can afford or power from your generator.

My Victron Multi-Plus has a 120-amp charger capacity and that's none-too-large for my 703AH FLA house battery bank. But, it worked fine all last summer for 3 months of cruising without plugging into shorepower once. The Victron was powered by my 3.5KW NexGen diesel generator.

My 100A Balmar alternator with MC-612 regulator was great, too.

If I had AGMs I'd want even more charging capacity to take advantage of their greater (than FLA) charge acceptance capability.

Re: battery chargers with multiple charging outlets (to charge multiple battery banks), these are almost always not needed. A good automatic relay like the EchoCharge can handle things quite well without the need for switching. Mine has worked flawlessly for almost a decade, as have those I've installed on customer boats.

Bill

[smac999]

Originally Posted by a64pilot

One thing to remember when sizing a charger is your house load, for instance if you have a load of 10 amps, then you only have 10 left for charging, if you have a 20 amp charger, and your running it at max capacity, which may mean excessive heat and a shorter life?
Also I believe that most battery chemistries benefit from high charge rates, your AGM's will, and I believe your flooded batteries will too, I believe a high charge rate will get the electrolyte moving via a convection current, a low charge rate will I think allow it to stratify, separate the acid concentration somewhat, in a flooded battery.

I will get some argument, but bottom line you can't have too big a charger, only too small.
Way, way too big may be a waste of money though

I agree

I was on a boat last Week with a 10a charger. The link lite said +10a. I turned on the salon lights and it went to -1.5a. A compleatly useless charger if any time is spent on the boat.

You should be at 10-20% of house bank plus average house loads.

[pdenton]

Right on. If a cruiser what size charger to charge X-amp/hr batteries with what y-amp charger for z-hour charging.
pdenton

[mitiempo]

Originally Posted by Scot McPherson

don't get a battery charger if you are going to replace the batteries really soon, just replace the batteries and THEN buy the charger to match.


The prosport is a great battery charger however. I love mine. The 20amp should be fine for your 220ah. Make sure if you DO buy the battery charger that you buy the charger for the number of batteries you have. If you have a 2 battery bank, then get a 2 battery charger...This is especially true of the prosports. a 3 bank charger will NOT operate with two batteries. It will just go into fault mode.

The Promariner 63120 is not a Prosport. It is a PronauticP designed jointly with Sterling in the UK. It will operate wit 1,2, or 3 banks. It has 12 charging programs as well as a custom program and is suitable for any type of battery.

I would buy the 63140 - the 40 amp version.