how to connect controller to two bat. banks

dancamp009

Seaman
Joined
Jan 13, 2007
Messages
64
I have just purchased two 18 w. solar panels and a 10 amp controller that I need to hook up to two separate battery banks (starter and house) that each consist of two 6 volt batteries in series.
My question is: How do I hook up the controller to two separate battery banks of equal power? Can I just split the power from the controller to each battery bank or do I need to buy two separate controllers (one for each solar panel).
thanks you
Dan
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: how to connect controller to two bat. banks

You have two panels but only one controller. There is no way to keep these systems separate. So your options are to parallel the two panels, feed that output to the controller, and then split the controller output to the two banks.

Option two is to get another controller. Connect one panel to one controller and that controller across the batteries in one bank. Repeat the process for the other bank.

Mind telling us what the house batteries are required to operate? The reason I ask is that an 18 watt panel produces 1.5 amps which will take forever to recharge a deeply discharged house battery. If you are using the panels to siimply maintain the batteries during periods of non-use, that will certainly work. Is theft and issue for you? Sorry -- don't mean to rain on your parade.
 

dancamp009

Seaman
Joined
Jan 13, 2007
Messages
64
Re: how to connect controller to two bat. banks

I only need enough to maintain my batteries at full charge during periods of non-use. So I'll settle for option two: get another controller. One for each bank rather than deal with combining bank issues.
Fortunately, theft is not an issue so far.

it's still a sunny parade . . .

thanx for ur help

Dan
 

mthieme

Captain
Joined
Oct 6, 2007
Messages
3,270
Re: how to connect controller to two bat. banks

You will find a second controller will not do what you want it to.
You will need to make the split after the controller.
I assume you have a battery selector switch? This should be good enough assuming it is wired properly (from the charging systems perspective).
Your two panels will supply 3 amps at peak charge. How many batteries are you trying to charge? While I've used .5 amp solar panel to keep a single battery topped off successfully (which I have on several items I don;t use frequently), I question the health of your batteries and charging system to begin with. Does everything operate correctly and how old are the batteries? Deep cycle?
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: how to connect controller to two bat. banks

Don't confuse the issue. He has no switch and was given two options, one of which was to split the output AFTER the controller. He has two independent systems and wants to keep it that way so two panels and two controllers will do that.
 

mthieme

Captain
Joined
Oct 6, 2007
Messages
3,270
Re: how to connect controller to two bat. banks

I think I was confused - not thinking that the two panels would be wired totally separate, one for each bank.
 

bruceb58

Supreme Mariner
Joined
Mar 5, 2006
Messages
30,537
Re: how to connect controller to two bat. banks

You could put a combiner between the two batteries. That would then be good for when you are just running the boat with the engine too. It would disconnect the two batteries at night.
 
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