Jumping Cranking Battery from Trolling Batteries

[Paul P]

My crankng battery ran down while on the lake last weekend so I ws unable to start my big motor. Luckily the trolling batteries were charged enough so I could troll back to the launch. This incident has motivated me to pursue the idea of putting a set of jumper cables in the boat in the event that this happens again so I can start of my troling batteries. Is this straight forward if i have a 24 volt set up for trolling?



Thanks



Paul

 

[Jim B]

Yep its pretty easy. If you jump from the positive and negative terminal of just one trolling battery you will get 12 volts. Its only if you put two batteries in series that you get 24.

 

[Texas Transplant]

I have been carrying jumpers for the boat since I got a new boat 5 years ago. Only needed them once, but I certainly did need them.



As Jim B pointed out, just jumpering directly off of the trolling motor battery post(s) of One battery, will give you 12v.



Tex

 

[William H. (Bill) Barham]

Like Tex I too have carried jumper cables for quite some time. I had an incident three years ago where my charging system didn't work somehow so on the lake all my batteries went dead. I tried to start the big motor to go back to the ramp and the battery was dead. So I said it'll take some time but I'll use the trolling motor to get back?.. Nope, they went dead too. So, my brother and I paddled back to the ramp. To make matters even worse, when we got back my truck wouldn't start because I left the lights on. Thank goodness there was a guy bank fishing who had jumper cables. Anyway, ever since then I have had cables in the boat.

An aside to this long story. While we were paddling the boat back to the ramp (one paddle btw) we passed within spitting distance three boats. Not one person in any of those boats would even look at us much less offer to help.



Bill

 

[Paul P]

Thanks for the info. I need just a little more clarification. I have a 2 batteries for my trolling motorguide. Is this setup typically wired in parallel or series? If I jump from the posts of one trolling battery, will this be a problem since the 2 are wired together?



Thanks



Paul

 

[Jim B]

a 24 volt setup is wires in series. You can jump from either battery in the system regardless of wether they are hooked together. If you need to jump just pick a battery and hoot to only that battery and you will get 12 volts.

 

[Texas Transplant]

Even if the batteries are connected to provide 24 volts, if you attach directly to one set of battery posts (directy on the battery) on 'one' of the batteries, you will only get 12 volts.



The key phrase is - directly to one set of battery posts.



Do NOT connect to what you think may be a common ground, and then to one positive battery post. Connect directly to the positive and negative terminal of one battery (only), and the other end to your cranking battery.



Here you are:

Tex

 

[Gene B]

I took an old set of cables and shortened them so they wouldn't take up so much room. Do it just like a car, from one battery to another.





Gene

 

[Paul P]

Thanks everyone!!! I'm going out at lunch to buy a set of jumper cables!



Paul

 

[Rusty Williams]

Just a thought ...but I usually just take out the cranking battery and replace it with one of the trolling batteries. This way you can use a much weaker battery because you don't lose so much amperage from the jumper cables. Just takes a pair of pliers to remove the wing nuts and you are set.



RW

 

[Steven Yates]

I have used jumpers once to get my outboard started and I also have run my trolling battery dead and used the jumpers starting battery to trolling battery to get me back to the ramp in a electric only lake a couple times

but I have a 12volt trolling motor.

 

[Humminbird Greg]

The last work boat I drove had a 12 volt trolling motor. After the first time I couldn

 

[Texas Transplant]

Greg,



Not if you jump 'directly off the battery posts'. You are correct. If your negative lead (on your jumper cable) is on something other than the battery post, you could be getting 24 volts.



And as you point out, if you have any concerns, simply remove the cables to the battery being used as the 'source'.



Tex

 

[william Clark]

I heard and found out for sure not too long ago that you can't jump an Optimax from your trolling battery. Not enough cranking amps. Just a note for Optimax owners.

I might look into a charge pack. Hopefully I can find one that will work. Clark

 

[JD Johnson]

Hmmm, if you have a 24 volt trolling system you could always get two sets of jumpers and use both batteries in a series to get enough amps to crank it.

 

[C C]

1st time out on my boat I accidently left the radio on, the next morning my main cranking battery was in bad shape and I could not get my motor started. I ended up getting a 900 amp power pack and right out of the box it got my 150 Optimax started on the 1st try. I now keep the power pack charged up and ready. The pack is small enough it can be kept on the boat.





Cass



Is it spring yet?

 

[Texas Transplant]

JD -



Two batteries in series gives you 24volts. You'd burn out the fuses and/or electrical circuits. Not a good idea.



Tex

 

[william Clark]

Thanks Cass, I was wondering if they make a power pack that would make the jump. Clark