Adding 24v Trolling Motor and 2 more batteries- will I explode?

[DanielRobertKelly]

I've been looking around to see if this will or won't work. Accidentally posted this question to a closed topic. Sorry.

Don't get too hung up on the inclusion of my solar panel. I'd just like some feedback on running the trolling motor this way.
For drained banks, I have a Genius Lithium-Ion starter that has proven to work, as well as a portablable rechargeable lead-acid jumper. So I don't worry about draining everything.

Right now the boat has two 12v batteries connected to the switch. My plan is to get two more, and parallel them into a 12v bank.

Right now, the Mercruiser 260 charges both batteries just fine, so I don't see any reason why it couldn't charge 1 bank, the other bank or both banks as well.

Thoughts? Here's the plan:

 

[Silvertip]

Got money for a new alternator now and then. Two more batteries means double the load on the alternator. And have you noticed that you have the pod and beg on both banks connected to the same terminals. So yes -- you will blow up.

 

[GA_Boater]

You stand a good chance of being stranded with dead batteries if you wire the four batteries like that. The only way to get 24 volts for the TM is with the battery switch in all.

Since the Genius Lithium-Ion jump starter has proven to work, are you experiencing drained batteries? You shouldn't have the need to rely on jump starters.

 

[DanielRobertKelly]

Thanks! These are the things I find it hard to get info on.

So what you're saying is that the load with the switch on bank 1 or bank 2 only will be the same as running on all now (which is normal operation).

 

[DanielRobertKelly]

After long storage starts are when I have had to use the jump. Not experiencing battery drain with normal operation.

Also, currently all is still parallel, my voltage read out is 12+ in All. I just want to switch to banks of two instead of banks of 1.

My attached layout was to series both banks with a second switch for the trolling motor only.

 

[DanielRobertKelly]

. And have you noticed that you have the pod and beg on both banks connected to the same terminals. So yes -- you will blow up.

Not clear on "pod and beg" connection. Switch is the old school bank 1 bank two switch, and worked fine all last season. I'm just making each bank two batteries instead of one, and then using the two banks in series for the TM. No?

 

[bruceb58]

You can't get 24V the way you have it wired up.

BTW, the negative cables never attach to a 1/2/both switch. There are only 3 connections.

 

[fishrdan]

Won't work (as Bruce mentioned) as the TM is only seeing 12V. And you can't throw a 24V series jumper in without shorting everything out.

What would work (even though it's seriously convoluted) is to use a Marinco 12/24 trolling motor/charging plugs and receptacle. Leave your existing 2 batteries connected to the battery switch and wire one of the batteries to the Marinco receptacle. Parallel wire the new pair of batteries together, and then connect them to the Marinco receptacle (Marinco receptacle has 4 connections). This will give you 2 pairs of 12V connections at the Marinco plug. Insert the series jumpered trolling motor plug and it will give the TM 24V, insert the parallel jumpered charging plug and it will allow all batteries to charge.

DON'T connect the wires from the 2 new batteries to anything but the Marinco receptacle as they need to be isolated (you can connect a marine battery charger with "isolated outputs"). Be sure to install manual resetting breakers on the new batteries + terminals, and also on the existing battery + terminal that goes to the Marinco receptacle.

Your alternator most likely won't do squat to charge all 4 batteries, or will take a long time to charge them. I have this type of setup, and even with a 100 amp alternator, it takes h-o-u-r-s to charge 4 batteries. Short runs here and there do help to put something back into the batteries, but it's a royal pain swapping plugs...