# Jumping starting battery with trolling battery?



## Foxthorn (Jan 26, 2005)

If my main starting battery dies on me while I'm on the water... Can I simply hook a set of jumper cables from one of my trolling motor batteries to the main battery and start the main motor this way??

Anything wrong with doing it this way vs. unhooking everything and re-attaching the leads to the other battery???


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## KS up north (Jan 2, 2004)

I think you lose too much juice through the jumper cables. I have a 90 hp evinrude and have tried to jump with limited success. I found that if your spare isn't at 100%, you are better off disconnecting main battery and installing trolling batt.


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## ESOX (Nov 20, 2000)

I'v both jumped and switched batteries. Both worked fine.


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## tdejong302 (Nov 28, 2004)

ditto I usually bring a charging pack with me too just in case the trolling motor is low. The charging pack hold a charge to jump start cars. It also has a flash light, air pump incase you find a flat when you get back. Very handy unit. I have save more then one stranded motorist with it.


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## Jason Adam (Jun 27, 2001)

You should have no problem doing what you described, unless you have a 24V trolling motor system, which you would just have to be carefull where you hooked up the jumper cables.


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## Foxthorn (Jan 26, 2005)

Jason Adam said:


> You should have no problem doing what you described, unless you have a 24V trolling motor system, which you would just have to be carefull where you hooked up the jumper cables.


Well... I do have a 24 volt system with two trolling motor batteries. So, what is the correct way to hook this up?


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## waterfoul (May 18, 2005)

I'd unhook (if possible) one of the trolling batteries and jump with just one... perhaps of you are this worried about having to jump start your starting battery, you should just get a new starter battery and not worry about it.


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## Foxthorn (Jan 26, 2005)

Actually I just got all new batteries... the reason I ask is because I did have a problem with the old one - and discovered the cables are not long enough so I actually had to remove the batteries to get the trolling motor battery close enough - plus it didn't fit in the starting battery tray, and they are very hard to get to in the first place (while on the water)... etc...

So, just wondering if this were to ever happen again if just using jumper cables would have been easier.

Can anyone explaine the technical reason why one of the trolling motor batteries would have to be disconnected? Hooking to just one battery wouldn't be pulling 24volts, would it?


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## Hunt4Ever (Sep 9, 2000)

You just need to look at your trolling motor battery setup. On my 24V system, the 24V connection made away from the battery terminals. I have taken meter readings on the battery terminals and they are 12 volts. You can not touch the 24V connection.


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## tommytubular (Jan 25, 2002)

Foxthorn said:


> Can anyone explaine the technical reason why one of the trolling motor batteries would have to be disconnected? Hooking to just one battery wouldn't be pulling 24volts, would it?



Two 12V batteries (battery 1 and 2) connected in series (positive of battery 2 to negative of battery 1) equals 24V potential at across positive of battery 1 and negative of battery 2. 

If you were to connect a set of jumper cables across the positive and negative of either battery 1 or 2 and then to the 12v starting battery you would be fine. it would only equal 12V potential. You do not have to disconnect the trolling batteries.


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## Jason Adam (Jun 27, 2001)

tommytubular said:


> Two 12V batteries (battery 1 and 2) connected in series (positive of battery 2 to negative of battery 1) equals 24V potential at across positive of battery 1 and negative of battery 2.
> 
> If you were to connect a set of jumper cables across the positive and negative of either battery 1 or 2 and then to the 12v starting battery you would be fine. it would only equal 12V potential. You do not have to disconnect the trolling batteries.


What he said.... Make sure you connect + and - to the same battery, and NOT to the positive of one and a chaisis ground or the other negative


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## Foxthorn (Jan 26, 2005)

Excellent!! Thanks everyone for the help.
I did take a reading on each trolling motor battery and individually they are showing 12 volt readings.

Thanks again!!


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## ih772 (Jan 28, 2003)

You will quickly destroy a trolling motor battery by using it as a starting battery. Trolling motor batteries are designed to deliver a fairly low amount of current over a long period of time. Starting batteries are designed to deliver a high amount of current over a short period of time.


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## tommytubular (Jan 25, 2002)

ih772 said:


> You will quickly destroy a trolling motor battery by using it as a starting battery. Trolling motor batteries are designed to deliver a fairly low amount of current over a long period of time. Starting batteries are designed to deliver a high amount of current over a short period of time.


I agree with the above statement.......however it beats rowing!


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## Foxthorn (Jan 26, 2005)

It depends on what kind of trolling motor battery you have.

What I'm using are the AGM type from Cabela's.

Group 27 - Dual Purpose
1200 marine cranking amps
950 cold cranking amps
180 reserve

This will be fine for an emergency backup - which I hope I'll never have to use.


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## Jason Adam (Jun 27, 2001)

Foxthorn said:


> It depends on what kind of trolling motor battery you have.
> 
> What I'm using are the AGM type from Cabela's.
> 
> ...


You're right, you are fine, everyone here probebly assumed you were using Deep Cycles for a 24V trolling system.


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## jstfish48162 (Mar 8, 2003)

those are nice batteries....my cousin just replaced his batteries with them. he had a cranking battery problem, and swithced batteries to get back to the ramp and forgot to switch them back. 
long story short, they were ruined. the cranking battery for being stored in the garage throughout the winter season, and the trolling motor battery for being used as a cranking battery.
ohwell, he/we got 3 seasons out of them...guess thats not too bad for stock batteries from the dealer.


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