On Board Charger Question

[TrailFndr]

I know this may have been covered in the past, but I can't find it so I figure I will ask the experts on the site...

I have a 12 volt trolling system, which I recently added a second battery in sequence to give me longer life while on the water.

I also have my starting battery.

Question, When I go to buy a on board charger, do I need a 2 bank, or a three bank system. Keep in mind, it is STILL a 12 volt system, and when I charge one trolling battery, the other charges also from the one connection, and they charge evenly, and drain evenly according to the Voltage meter.

[WALLEYE MIKE]

Thats the way I did mine(with a 2-bank) when I had 12-volt

[FishTales]

Trailfndr
Your right this was just covered recently and I was curious too.
You have two batteries for the trolling motor but still considered 12 volt system.
What you have to keep in mind is you still have what is considered as a two bank system.
I would suggest you get a two bank charger, for a couple of reasons.
If you try to do this with a one bank charger, you would have to tie the starting battery in with the trolling batterie's, I don't think this is a good idea.
There are some difference's in the chargers too, they come with different charging amp's per bank.
Most that I seen will charge one bank and when it has a full charge that side will shut down.
Some chargers will actually switch over to help charge the other bank, ie: your starting battery gets up to full charge and instead of shutting down it will switch over and help charge the trolling batterie's.
Now that I have thrown all that confusion at you, here are some samples to get you started looking.

http://www.basspro-shops.com/servlet/catalog.TextId?hvarTextId=45195&hvarTarget=search&hvarAID=

http://www.cabelas.com/cabelas/en/templates/product/horizontal-item.jhtml?id=0019015015766a&navAction=push&navCount=2&indexId=cat600056&podId=0019015&catalogCode=ID&parentId=cat600056&parentType=index&rid=&_DARGS=%2Fcabelas%2Fen%2Fcommon%2Fcatalog%2Fitem-link.jhtml.1_A&_DAV=MainCatcat21276&hasJS=true