Two batteries on three bank charger?

[Npkman]

Previously I had a three battery setup (two for trolling, one for starter/electronics) with a three bank charger. Because of some changes I made I now have four batteries (two trolling, one starting, one for electronics). I now have an additional two bank charger that I hooked the charging and electronics batteries to - and hooked the two trolling batteries to the old three bank charger. I simply isolated/secured one charger lead from the charger (ProSport 20 Plus three bank charger) and hooked the other two charger leads to the trolling batteries.



Does anyone have experience with only two batteries on a three bank charger? Seems to be conflicting information out there.

[REW]

The largest % of on board battery chargers utilize a separate charger for each bank.

Hence, you can use one, two, or three batteries on a 3 bank changer for most on board chargers with 0 issues.

Take care

[Snowking]

I think most people recommend hooking all of the leads up. So you would have 2 banks hooked up to one battery. Instead of leaving one positive and negative cable electrical taped up.

[clawman]

Originally Posted by Npkman

Previously I had a three battery setup (two for trolling, one for starter/electronics) with a three bank charger. Because of some changes I made I now have four batteries (two trolling, one starting, one for electronics). I now have an additional two bank charger that I hooked the charging and electronics batteries to - and hooked the two trolling batteries to the old three bank charger. I simply isolated/secured one charger lead from the charger (ProSport 20 Plus three bank charger) and hooked the other two charger leads to the trolling batteries.
Does anyone have experience with only two batteries on a three bank charger? Seems to be conflicting information out there.

If you secure the unused leads so they can not short out I can not see why it hurts anything to have an unused bank. Have you asked the service dept of the charger manufacturer?

[Npkman]

I have not been able to make contact with a real person at Promariner to ask them. Nor have I received a return call.

What I have found on-line is to; 1) simply secure the unused lead(s) and go on and 2) connect the extra lead to one of the other batteries. What I can't find out is 1) if the lead is secured, are the extra amps simply dished out to remaining leads, 2) if the extra lead is attached to a battery already hooked up, how does that affect charging rate of each attached battery and 3) is there any negative long term effect on battery life from these scenarios? The information on-line is mixed.

[Ltrain]

Originally Posted by Npkman

I have not been able to make contact with a real person at Promariner to ask them. Nor have I received a return call.

What I have found on-line is to; 1) simply secure the unused lead(s) and go on and 2) connect the extra lead to one of the other batteries. What I can't find out is 1) if the lead is secured, are the extra amps simply dished out to remaining leads, 2) if the extra lead is attached to a battery already hooked up, how does that affect charging rate of each attached battery and 3) is there any negative long term effect on battery life from these scenarios? The information on-line is mixed.

First what I would do in your situation is double up the leads on the two bank charger to one battery then hook the remaining three batteries to the three bank charger.


To answer your questions: there are no extra amps-each bank is rated for so many amps so if its a 30 amp charger it's 10 amps per bank, if you don't use a bank you don't get the amps
If you double up the leads you double the amps and almost halve the charge time.
I double my leads to my starting battery as I have a four bank and a two bank charger for 5 batteries. Works great. The 2 bank is 5 amps per bank and the 4 bank charger is 15 amps per bank so my house and trolling motor batteries get 15 amps and the starter gets 10.

[Npkman]

Thought I would report back what I found out. I called Promariner again and fairly quickly got a response back from Promariner technical support.The guy I talked to seemed to be very knowledgeable and personable. Hats off to Promariner Technical support.



His first response was to connect both set of leads on the two bank charger to the single starter battery and then have three batteries on the three bank charger. For several reasons I did not want to do that (pulling new wires, varying demands on batteries, etc.) - so he told me the following way that would be just as good.



His recommendation was similar to a couple of earlier responses on the thread. He said that on the 3 bank charger that has the two trolling motor batteries I should connect the leads from the bank that has a fuse on only one of the leads (marked as starter battery connection on mine) along with the next in line bank that has a fuse on both leads - to a single battery. The remaining bank also has two fuses (one on each lead) and should be connected to the remaining battery. He indicated that the charger is looking for a minimum of 2.5 volts on each bank of the charger in order to work correctly.



Both of my chargers are Promariner, don't know about other brands.

[GBS]

Originally Posted by ltrain

First what I would do in your situation is double up the leads on the two bank charger to one battery then hook the remaining three batteries to the three bank charger.


To answer your questions: there are no extra amps-each bank is rated for so many amps so if its a 30 amp charger it's 10 amps per bank, if you don't use a bank you don't get the amps
If you double up the leads you double the amps and almost halve the charge time.
I double my leads to my starting battery as I have a four bank and a two bank charger for 5 batteries. Works great. The 2 bank is 5 amps per bank and the 4 bank charger is 15 amps per bank so my house and trolling motor batteries get 15 amps and the starter gets 10.

Not so with these chargers. Each lead is capable of delivering the total output. It divides it down to reflect the current state of each battery. So with a 20 amp charger, if one battery needs 15 amps, and the other 5, that's what it does. If one needs 20, and the other is full, then the one gets 20.

I've got an older 2 bank of this brand, that I sometimes use to charge a utility 12v. I currently have one line taped off. I'm interested in the "correct" answer, but never made the effort to contact ProMariner. A few years ago I had a question, and they were really good about answering their phone, and getting the answer, so perhaps the OP may want to try that...

Later edit: So, question answered just as I was typing my post! Good to know, sounds like I should run both of my leads to the single battery....

[Ltrain]

Originally Posted by GBS

Not so with these chargers. Each lead is capable of delivering the total output. It divides it down to reflect the current state of each battery. So with a 20 amp charger, if one battery needs 15 amps, and the other 5, that's what it does. If one needs 20, and the other is full, then the one gets 20.

I've got an older 2 bank of this brand, that I sometimes use to charge a utility 12v. I currently have one line taped off. I'm interested in the "correct" answer, but never made the effort to contact ProMariner. A few years ago I had a question, and they were really good about answering their phone, and getting the answer, so perhaps the OP may want to try that...

Later edit: So, question answered just as I was typing my post! Good to know, sounds like I should run both of my leads to the single battery....

Thanks GBS for correcting my response about amps per bank with these ProMariner chargers.I hate giving out false info. I will add this is not like most chargers and I wonder if these individual banks are truly isolated . It would seem for this on demand technology to work there would have to be a common ground. I'm just thinking out loud here, not saying that is true, in any case thanks GBS for clearing that up.