wiring two batteries

fishermanof93

Seaman Apprentice
Joined
Feb 3, 2015
Messages
34
I have a small aluminum flat bottom and was thinking about adding a second battery. I don't have electric start but I have two locaters and a livewell on it. not sure if I will even need a second one or not but my trolling motor can be switched between 24 and 12 volt. I think I would get a significant amount of more power running as 24 but I don't know that for sure. what my question is, is it possible to hook these batteries up in series and parallel. so that I have the higher voltage and longer life for the electronics.also if they were in series I would assume I can just run a standard charger on one of them and they will both charge? I use to do a lot of car and stereo wiring so that's not a problem just having a problem thinking threw this. if the picture doesn't make since sorry I am not good with paint.Untitled.jpg
 

UncleWillie

Captain
Joined
Oct 18, 2011
Messages
3,995
STOP!!!
If you wire it the way you show it in the drawing, You will destroy the batteries before you could dive for cover.
You have both batteries dead shorted. Smoke and fire in less that a second will be the result! :eek:
You can wire then in Series OR Parallel, Never both ways!
 
Last edited:

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
40,581
+1 agree, best suggestion would be leave it as 12V only unless you install a third battery for electronics
 

UncleWillie

Captain
Joined
Oct 18, 2011
Messages
3,995
... my trolling motor can be switched between 24 and 12 volt.
I think I would get a significant amount of more power running as 24 but I don't know that for sure...

12 volts is higher current at a lower voltage. Heavier gage wires needed
24 volts is lower current at a higher voltage. Lighter gage wires needed.

12 volts or 24, the power is the same and the batteries will last just as long.
 
Last edited:

fishermanof93

Seaman Apprentice
Joined
Feb 3, 2015
Messages
34
can I do this and if so which one of the batteries would be better to run the depth finders off of to reduce 'noise" Untitled.jpg
 

2 Eagles

Petty Officer 1st Class
Joined
Apr 4, 2011
Messages
206
Is your motor wired to the charge battery. If not then here are some wire diagrams that might help. On the frist one just use the ones you have. If you don't have a battery swith then just wire one battery to the fuse box. If you need a wire plan with just the items you have let me know. I need a list of what you need on it.
 

Attachments

  • 24v System.pdf
    138.9 KB · Views: 0
  • Trolling Motor Plugs.pdf
    66.2 KB · Views: 0
Last edited:

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,758
You mentioned in an earlier post that your motor can be run on 12 OR 24 volts. Your last diagram would prevent 12 volt operation since that system provides ONLY 24 volts. You also mentioned using a standard 12 volt charger to charge both batteries. That will work with your last diagram ONLY if you charge them separately. You cannot charge both batteries simultaneously in a 24 volt system with a single 12 volt charger. In your last diagram you would connect 12 volt accessories to the battery on the right. This avoids any problems from accidental grounding should you have them connected to the battery on the left. Look carefully at your diagram. Note that you have the NEGATIVE wire from the troller connected to that battery. That's the battery you want to use for 12 volt accessories. It doesn't matter if the battery is on the right or left -- just that whatever battery has the negative trolling motor wire connected is the one you want to use. You also need a fuse or breaker in the POSITIVE lead going to the motor and that should be placed within 6 - 12 inches of the battery. As mentioned, running accessories from a 24 volt system will mean those accessories deplete one battery quicker than the other so troll-time will be reduced accordingly.
 
Top