wiring in a blue sea and acr switch

ngt

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I've got a set of batteries in parallel and a starter battery. I have a 2 bank charger but soon will be upgrading to a 3 bank 15 amp charger. I don't want to wire it up and then have to redo everything so I'd like to set it up for the 3 bank charger. Not sure if this even makes a difference. How would you wire up that setup ?

thanks
 
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A bank is any thing that's connected with 12v potential. So one battery or more than one battery (connected in parallel) are technically a bank. At the moment you have 2 banks and a 2 bank charger. Now if you are changing the charger you have to realize that there is a big difference between a isolated 3 bank charger and a non isolated charger. A non isolated charger will have one dc-neg and 3 dc plus wires. This is to charge 3 banks that are connected all the time using dc negative but not connected all the time on the dc positive side.
If its isolated 3 bank then its really 3 battery chargers stacked on top of each other. They are really designed to treat one battery on each bank and each bank has 2 wires going to it. There is no common between the batteries so the charger can monitor and control the charge to each battery. They also do not care how the batteries are wired together as each bank is just one battery.
 

ngt

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A bank is any thing that's connected with 12v potential. So one battery or more than one battery (connected in parallel) are technically a bank. At the moment you have 2 banks and a 2 bank charger. Now if you are changing the charger you have to realize that there is a big difference between a isolated 3 bank charger and a non isolated charger. A non isolated charger will have one dc-neg and 3 dc plus wires. This is to charge 3 banks that are connected all the time using dc negative but not connected all the time on the dc positive side.
If its isolated 3 bank then its really 3 battery chargers stacked on top of each other. They are really designed to treat one battery on each bank and each bank has 2 wires going to it. There is no common between the batteries so the charger can monitor and control the charge to each battery. They also do not care how the batteries are wired together as each bank is just one battery.


It's the minn kota 15amp 3 bank charger. It's isolated. I was going to have one set of wires on each of the batteries in parallel and one set to the cranking battery.
 

UncleWillie

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You have two batteries in parallel. That is One battery electrically.
You are going to add and ACR. The 'C' stands for CHARGING. The 'A' makes the 'R'elay AUTOMATIC.

As soon as you start charging, and either the Start Battery, or the Paralleled Bank, reach 13 volts,
the ACR is going to parallel all three of them together for the purposes of charging.
You will now have ONE Battery for Electrical/Charging purposes.

You only need a Singe Bank Charger. That is the whole purpose of the ACR.
One Alternator, or One Charger, will charge All the batteries.

A three bank charger would be practical in the case of a single starting battery and two other batteries wired in series to provide a 24 volt bank. You would Not want ot install and ACR in this situation.
 
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It's the minn kota 15amp 3 bank charger. It's isolated. I was going to have one set of wires on each of the batteries in parallel and one set to the cranking battery.

That's a good charger just hook the leads to the batteries and you will be good to go. The leads marked battery one goes to the cranking battery the others don't matter which battery. Test where you are installing before drilling as the leads are just long enough for most boats.
 

UncleWillie

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It's the Minn Kota 15amp 3 bank charger. It's isolated. I was going to have one set of wires on each of the batteries in parallel and one set to the cranking battery.

With it wired that way; When you first apply power to the charger, you will get 15 amps on the Start Battery and 30 amps on the paralleled battery.
A minute later the ACR will energize and you will have a single 45 amp charger going to the three parallel batteries.

If you currently have a two bank, 15 amp charger (30A Total), you will see very little difference in performance by upgrading to a 45 amp total charger.

The three batteries will be drawing 45/30 amps for only a short period at the beginning of the charge.
They will both spend the vast majority of the time supplying less than 20 amps.

A 45 amp charger has 50% more Maximum current available, but does not charge 50% faster than a 30 amp charger.
 

ngt

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My current 2 bank charger is isolated, but only 5amps per bank and it's a Guest.
 

UncleWillie

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My current 2 bank charger is isolated, but only 5amps per bank and it's a Guest.

Is the proposed 3 bank, 15 Amp Charger, 3 banks of 5, 15 Total?
or 3 banks of 15, 45 amps total?

If a 3x5, 15 amp total charger, you might want to rethink spending the money to see only a marginal improvement in charging time.

With the ACR, it would make more sense to attach both banks of your 2x5, 10 Amp charger to the paralleled batteries.
Once they reached 13v, the start Battery, which likely needs little to No charge, will be paralleled in by the ACR and just receive a small topping charge.

Assuming the parallel, Non-Starting Bank is the power for a trolling motor;
If the goal is to get the batteries recharged during a lunch stop so you can make a second trip the same day, the 45 amp charger would be justified. Attach all 3 banks to the two paralleled batteries.
The 10 , 15 or 45 amp chargers will all get the job done if you won't be needing them till the next day.
 
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ngt

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Is the proposed 3 bank, 15 Amp Charger, 3 banks of 5, 15 Total?
or 3 banks of 15, 45 amps total?

If a 3x5, 15 amp total charger, you might want to rethink spending the money to see only a marginal improvement in charging time.

With the ACR, it would make more sense to attach both banks of your 2x5, 10 Amp charger to the paralleled batteries.
Once they reached 13v, the start Battery, which likely needs little to No charge, will be paralleled in by the ACR and just receive a small topping charge.

Assuming the parallel, Non-Starting Bank is the power for a trolling motor;
If the goal is to get the batteries recharged during a lunch stop so you can make a second trip the same day, the 45 amp charger would be justified. Attach all 3 banks to the two paralleled batteries.
The 10 , 15 or 45 amp chargers will all get the job done if you won't be needing them till the next day.

No, it's a 15amps per bank, 3 bank Minn Kota Charger. So by what you're saying, it's 45 amps. It runs about $350 shipped on Amazon. I have my current 2 bank charger set up with both 5 amp banks on the parallel batteries and I use a second 6 amp charger for the cranking battery. The parallel batteries are for my downrigger and trolling motor, while my cranking/starting battery is for the starter and my fish finder.

So what you're saying is that my Guest 5 amp on each of the two banks, both hooked up to the parallel batteries, with the blue sea ACR stuff would be enough if I was only going out fishing during the day and could charge it overnight?
 

UncleWillie

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...So what you're saying is that my Guest 5 amp on each of the two banks, both hooked up to the parallel batteries, with the blue sea ACR stuff would be enough if I was only going out fishing during the day and could charge it overnight?

Yes! Your 2x5,(10 amp) charger should be able to charge your parallel Batteries in under 10 hours with a typical drain.
and in ~15 hours if you really ran them down farther that you should.
I will assume you are already using this charger, with only one bank on the paralleled batteries. How has that been working?
Both banks on the paralleled batteries is going to make it even faster. Not twice as fast, but noticeably faster.

The ACR is also going to allow the Alternator to put a charge into the paralleled batteries during the return trip to the dock.
This head start on the charging is also going to shorten the total charging time.

In any event, it would be worth trying your present charger before shelling out the $350 if the current charger will meets your needs.
If you find the 10amp charger does not meet your expectations you can always upgrade later.

It is certainly worth a try.
 
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ngt

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Ok, thanks! I'll give that a go first.
 
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