TROLLING MOTOR HELP

[rudycard72]

I am having trouble with my Motor Guide bow mounted trolling motor recently and I was hoping for some help. About  weeks ago I noticed my TM wasn't staying as strong as long as it used to so I checked the water levels in my batteries. The water was low in both (both were purchased last year) so I filled them up and charged them. I had fished three or four times since and everything seemed to be fine. Then I went out a few days ago and it would only work on the 24v side of switch but I could tell I was only getting 12vof power. When I got home I charged both batteries with a single charger rather than using my on board charger, when they were both done i tested it in my garage and both 12v and 24v side of switch worked good but when i got on the lake i soon noticed the same problem except this time the 12v side was working but barley spinning, 24v side working but at only 12v of power. When I got home i hooked up single charger again and topped one battery off because it was mostly charged . The other battery had no charge so i hooked it up and began charging. About 3 hours later i went out and checked it and the battery that was charging and the charger were very hot. So i unplugged charger and disconnected it from the battery but when i touched the negative clamp it was red hot and melted the plastic handle on clamp. Any help is appreciated.   Thanks.

[Revtro]

Is it wired in Parallel or in Series?  When I got my boat, my Motorguide was wired in Parallel.  I ended up with pretty much the same type of problem.  I contacted Motorguide and they told me to re-wire the batteries to run in Series.  That fixed my problem.  They don't recommend it to be wired in Parallel. 

[rudycard72]

Its wired in series

[Revtro]

Just to clarify, the two batteries are connected together via a jumper then right?  I'd be surprised to see them wired in series since you have a 12/24 volt switch...  Usually when the voltage is switchable, they'll be wired in paralell (2 cables coming from each battery to the front plug.)  If they are wired in series and you're having one battery die, then you have a bad battery.  That sounds like what you have going on here.  Sorry I can't be more helpful. 

[rudycard72]

I stand corrected,the batteries each have cables going to the TM through a breaker. There are no cables going from battery to battery. I will try and connect them parrellel. Thanks for your help.

[djkimmel]

If you connect them parallel, you will only get 12 volts, just lasts longer.

Sounds like your trolling motor plug is set up with a jumper to get the 24V when needed from the two batteries that are not wired in series or parallel at the back of the boat.

You may have to change how your plug receptacle or trolling motor plug is wired if you change how your batteries are wired at the back (the metal jumper in the plug or receptacle creates the 24V series when you switch to 24V).

Electrical is not my expertise, so I would need to know what wires are coming from the back of the boat to the trolling motor plug receptacle, and where any metal jumper is inside the plug or receptacle before I could figure out your setup exactly. I have a 24/36, but my spare is a 12/24 and I have a chart in my manual of how that is hooked up differently if necessary.

Regardless, I agree with Rev - sounds like your main issue is that you have a bad battery, which will mess up a series application no matter what. If the battery post is getting real hot, there is too much resistance and improper charging. Maybe a dead cell. A voltage meter is real handy for checking that out.

[Revtro]

Agreed.  A bad battery is most likely what you have going on here.  Since you have 4 cables coming from the battery and no jumper, it is probably wired with a jumper at the plug so that it's switchable.  This was exactly how mine was wired. You can wire them in series, but then you'll only get 24 volt. Heck, you don't need 12 volt anyway, so that's what I would do. 

Wire them in series with a jumper.  Make sure you do this right or you will short out the batteries.  The jumper goes from a positive terminal to a negative terminal on the other battery.  Whatever you do, don't jump two negatives or positives together.  Then wire it to the two terminals on the plug that are appropriate to get 24 volts to the proper terminals on the trolling motor. 

Once you do that and you're certain it's wired correctly, check the charge on the batteries and use the motor.  Then check to see if one battery is draining and the other is not.  If this is the case, you have a bad battery.  Sounds like you already know you have a bad one though.  In my case, I nearly ruined a battery because the jumper in my plug was shorting out and only draining one battery.  It's not the best way to wire a trolling motor in my opinion.  Motorguide told me to re-wire it immediately and I did.  No problems since. 

The only other thing to keep in mind is how you have your onboard charger wired. 

I'm in eastpointe.  If you don't have any experience wiring batteries and could use the help, I'd be glad to help you out. 

[cameraguy]

It seems to me that the first thing you want to do when having battery problems is make sure that all connections are clean.  Clean the conncectors and battery posts with a small wire brush.  If you still have the same problem after cleaning, then proceed to find another solution.  Since you have batteries that you can fill with water, buy a good hydrometer and check the batteries.  You mentioned that the batteries were a year old.  Were they kept in the boat either outside or in an unattached garage over the winter?  In my past experience this can harm the batteries. 

Then, if the batteries check out okay then have someone who knows what they are doing assist you in checking the wiring.  If that means taking it in to be serviced, then that might be the best option.  You really don't want to change the wiring unless you are absolutely sure you know what you are doing.  Like Dan said, if you switch to wiring in series and the boat had been rigged for parallel, the plug may have to be rewired, as well. 

Also, how big is your boat and what size batteries are you using?  You might be able to step up to the next size of battery.  I have had all kinds of problems over the years with batteries not lasting all day (and being shot in one year) even after a thorough charge, until I got the 31 series batteries.