Adding a battery for a trolling motor

[610Ved]

Hey all, looking for some help rewiring my battery set up. Previously had two group 24 batteries (house and cranking) set up to power the motor and electronics. Both batteries were run through a blue seas 1, 2, or 1+2 switch. Heres a picture of the previous set up.
 


I'm in the process of adding a 24v minn kota trolling motor. I don't really want to add two more batteries so I decided on replacing the one group 24 house battery with two group 27 deep cycle batteries. I think I get how to wire these through the switch so that I have the cranking batteries separate from the two house/trolling motor batteries. My thought was to connect the two new house batteries in parallel and remove the negative to negative connection between house and cranking?

This is how I have it with the 3 battery set up. The two smaller gauge black wires are returns from bus bars. Attaching the trolling motor should be as easy as connecting the pos and neg to the correct terminals on the 27 group series?

[Fish Head]

Far as I can tell your 27 group is in parallel and not in series. You have to go neg to pos with a cable to put them in a series and get 24v.

[610Ved]

Gotcha I understand the difference there. This might help. I basically rewired this entire boat following new wire marine's guidelines and used their switch panel.



I just am somewhat lost on how to connect the two house batteries that are in a series into the battery switch without frying all my electronics at 24 volts. I would like to still be able to once on anchor or trolling motor switch the load to the house batteries. Is this possible with the current set up or do I need another switch or figure out something else?

[RickK]

You want to keep the two banks isolated. So don't put them on the same switch. The trick will be how to charge the banks.

[Tampa Bay Mike]

I used New Wire Marine as well when I did my boat. I only went with two batteries but I remember one of their diagrams has a 3 battery option with multiple switches. It may be worth a call or email to them to ask. They were really helpful when I did mine.

[610Ved]

Couldn't find that new wire diagram but did find another that added some clarity. So my cranking battery is actually a dual purpose that I've used to power all my electronics when at anchor before due to forgetting to flip the switch. Having that alone as my cranking and house isn't an issue.



This seems like the best solution I came across of without adding a second switch. I can still flip the battery switch and use part of the house to help crank the motor if needed. I'm most likely going to get a 3 bank charger to just replenish all three after a day of fishing. Tested it out and worked without an issue.

[Fish Head]

This looks like the solution for being able to charge all 3 batteries from the running motor. No switches and looks like a set and forget setup! Cranking battery protected. Sounds to good to be true.Anybody try this system yet? TrollBridge 12x24

[RickK]

That troll bridge looks to be slick. Looks like something I'll need. Thanks for posting it.