Dual Battery Charger

[brain_rinse]

Thanks, David! Would you still recommend an in-boat charger if the boat is stored in an unheated garage for the winter? Or would it be better to take the batteries out of the boat and use a stand-alone charger in a heated area?

[EarmarkMarine]

doug,

Other than CTEK chargers which claim to use pulse technology, we don't have first hand experience with specialized desulphators. Sorry, I can't help on that one.

But on a sidenote, our approach to battery chargers has been formed by the engineers who design chargers for the leading manufacturers serving the boating industry, particularly fishing. The typical tournament fisherman is using three group 31s to drive their trolling motor. The engineers assert that desulfation, especially in deep cycle flooded batteries, is a function of having enough current capacity to chemically excite the battery. And, that this can't be done with a small maintenance/trickle/tender type charger.

We've seen that battery brands of all types tend to get blamed for poor performance and short lifespan when the true cause is an inadequate charger, no charger at all or a bad charging regimen.


Brian,

We're in Texas so the cold temperature is not a factor. You may need to get an answer on that from someone closer to home.

David
Earmark Marine

[cab13367]

brian,

We usually begin with the Guest 2611A 10 amp dual bank charger (5 + 5).

But I really like the ProMariner ProSport 12 and 20 amp models. They may be a little less protected from direct exposure to water but since they're not potted they cool very well. And the distribution scheme will deliver the full capacity to the bank in need. The ProSport 20 is our best seller. Then we graduate up to the ProTech 1240iPlus and to Progressive Dynamics for 60 or 80 amp models. We've got detailed info on our website. Get with me about overall wiring schemes if you're interested.

David
Earmark Marine
[email protected]

David,

I have two batteries in my boat, one is the stock battery that starts the engine and runs the engine accessories, and the other is Kirkland Group 27 battery rated at 750 MCA, 600 CCA, and 115 amp hours that runs two amps, a Kicker 700.5 and a JL Audio M6600. I would like to install an onboard battery charger as I have found that our "float and listen to the stereo time" is much greater than our "engine running while boarding & surfing time" so that the stereo battery does not fully recharge just from the boat's alternator.

So my question is, will the ProMariner ProSport 12 Gen 2 be adequate for my application? I think the start battery is pretty much being charged fully by the alternator or close to it so when I plug the ProSport 12 in when I get home, it should send most of the 12 amps to the stereo battery which is in keeping with your guidelines of 1 amp charger output per 10 amp hours of battery capacity for choosing a battery charger.

Please advise.

Thanks,

Al

[EarmarkMarine]

Al,

My statement is predicated on collective amp/hour rating, not singular. The ProSport 12 could get you by but the 20 is a better choice.

After a protracted period at rest your stereo battery may be fully depleted and could potentially pull 25 plus amps initally. Your boat pulls 15 amps to run without DC lights. Your stereo may draw 50 amps. If your alternator isn't running at a high rpm its not generating anywhere close to its full capacity. If the total demand exceeds the alternator supply then the stereo battery and starting battery will level to some degree. So you may not be putting your boat up with the starting battery topped off.

The real determining factor is your individualized usage. If you frequently run your stereo battery below 12 volts then step up to the 20.

David
Earmark Marine

[cab13367]

David,

Thanks for the reply. What is the advantage of going with the 20 vs the 12? I understand that the 20 will charge the battery faster than the 12 but what is the advantage to charging the battery faster?

Thanks,

Al

[EarmarkMarine]

Al,

I don't consider faster charge time the issue. Its irrelevant mostly.

As you discharge a battery, the sulphates leave the solution and bond to the surface of the lead plates. As you recharge, the sulfates return to the solution for a concentrated sulfuric acid. When you undercharge or leave the battery discharged for long durations, the sulfates tend to bond permanently. Once the sulfates are permanently attached to the plates the battery may heat up, take a surface charge but won't accept a deep and lasting charge. Thus, a shortened playtime at rest and shortened overall lifespan.

It takes a prescribed amount of current (10 to 13 percent of amp/hours) to chemically excite a battery in order to properly desulphate and condition.

David
Earmark Marine

[cab13367]

Al,

I don't consider faster charge time the issue. Its irrelevant mostly.

As you discharge a battery, the sulphates leave the solution and bond to the surface of the lead plates. As you recharge, the sulfates return to the solution for a concentrated sulfuric acid. When you undercharge or leave the battery discharged for long durations, the sulfates tend to bond permanently. Once the sulfates are permanently attached to the plates the battery may heat up, take a surface charge but won't accept a deep and lasting charge. Thus, a shortened playtime at rest and shortened overall lifespan.

It takes a prescribed amount of current (10 to 13 percent of amp/hours) to chemically excite a battery in order to properly desulphate and condition.

David
Earmark Marine

Thanks David, that's the answer I was looking for.

[cab13367]

David,

I have the Blue Sea Add A Battery ACR installed - any compatibility issues between it and the ProSport 20?

Thanks,

Al

[viking]

Hey Al,
I have the Blue Seas add-a-battery too. Been charging my batts seperately while still in the boat. I noticed that when I have the switch to the "on" position that they Combine and the green LED lights up indicating so. That is pretty straight forward as it senses the charge and then combines for the process. It is the same when the engine is running and alternator is charging.

However, I switched it to "OFF" over the weekend to seperately charge them and the green LED still came on after a few moments indicating they were combined? I got a little puzzled? Any input?

[cab13367]

Hey Al,
I have the Blue Seas add-a-battery too. Been charging my batts seperately while still in the boat. I noticed that when I have the switch to the "on" position that they Combine and the green LED lights up indicating so. That is pretty straight forward as it senses the charge and then combines for the process. It is the same when the engine is running and alternator is charging.

However, I switched it to "OFF" over the weekend to seperately charge them and the green LED still came on after a few moments indicating they were combined? I got a little puzzled? Any input?

viking,

The battery switch does not turn off the ACR. You have one cable going from the ACR to one battery and another cable from the ACR to the other battery. Turning the switch to "OFF" does not change that so the ACR is still sensing the charging current and combines the batteries once the battery your charger is on reaches a certain voltage.

I have a resettable breaker on each cable so when I want to charge just one battery, I open the breaker on the cable for that battery. You should have a fuse where I have a resettable breaker so you can accomplish the same thing by puling the fuse. See pic below.

[IMG][/IMG]