I have the following diagram for my all electric boat.

I have 2 24 volt 82lb thrust t motors and 4 batteries and 2 big foot switches at the front of the boat. I have the batteries rigged in a series. Not sure if this matters but my series cable has a normal loop that you put around the threaded bolt on the battery and fastened with a wingnut. The other end has a car type end that goes around the lead post and fasten with a bolt/nut.

The purpose of the 2 big foot switches are to prevent myself from going to the back of the boat to turn on the 2 trolling motors.

BTW I have the foot control trolling motor on the front deck working 100% hence it's not included in the picture.

But anyway. I have the trolling motors working but I think it's only getting 12 volts worth of power. Tell me what I am doing wrong or I ain't gonna get to go hawg huntin on Varner this week!!! argghhh

Can someone redraw my diagram the way it's supposed to be rigged?? If you need to look at the big foot switches and not sure what they are here is a link.

http://www.outdoorexperts.com/bigfoot21tro.html

The big foot switches have 2 black wires coming out of the back just as it is shown in my wiring diagram I have drawn. Anyone gots a clue?? Thanks in advance

T Mike

Clueless in Gawgia

Triton_Mike,

Those Digrams are Correct for 24V. have you used a voltmeter to check the voltage at the motors?

Paul

There's nothing wrong with your wiring.  As mentioned, I would use a voltmeter and start measuring voltage drop.   Measure across the negative and positive  post on the batteries where you have your motor and bigfoot cables connected with motor on high and loaded (in the water).  Should read a little over 25 volts.  Now measure it at the motor's negative and positive cables, should be the same, if not you are getting a lot of resistance from somewhere.   With the current those motors pull, should take long for a lot of heat to start building with motor on high, but you can follow back with the meter until you find the drop, if there is any.  If it's at the batteries, get some more.

Ben,  I will get a volt meter tommorrow.  If there isn't 25 volts coming out what do you figure my problem is???  I am using 6 gauge marine wire FYI....

Mike

Go to a auto parts store an get a cable with a lug on both ends & use those for your series cables. It will make a much better connection & less of a voltage drop.

Mike,

That's exactly how you do it. That's how mine are done minus the need for 24V. Just make sure all of your connections are solid. If you are useing the 4ga automotive wires for your series connections that should be fine. 25V is rite on. I can't wait to see the boat.

Not sure what 6ga marine cables is, if it's another name for 6ga fine strand battery cable, it should be fine.   Cable ends should be the heavy copper, NAPA and welding supply stores have them.  If you don't have a crimper, either the one you hit with a hammer or the $600 ones that look similar to bolt cutters, be sure to solder the ends with resin core solder.  A Benzomatic tourch will be needed to do this.  I solder them after crimping just to be sure of a good connection.  You can take a very dull (rounded edge) chisle turned and centered long ways with the cable end and smack it a coule of time with the hammer, not hard enough to cut throught the copper but enough to fold it down hard and the wiring, then solder.

I would make my first check across the TM negative and positve.  If voltage across them is 25+ and does not drop much when loaded, there's nothing wrong with batteries or wiring.

Are you using new batteries?  Fully charged they should give you 25.6 - 26 VDC and should not drop more than a couple of tenths when under load of motor.  If dropping a volt or more, batteries are no good.  Check this on the lead post of the batteries and not the cables, the check it one the cables.

If you are getting a voltage drop, measure from the lead post where the foot switch cable is connect to the oposite cable coming out of the for switch going to TM.   You should not read any voltage when the switch is closed, if you do, the voltage you read is caused by resistance in the foot switch.

Slightly off topic question for BEN-

Would there be more or less resistance if they were wired paralell as opposed to in series?

Wired parallel would only give him 12 volts and would not run his 24 volt motor. He has to have a series circuit to get his 24V.

Any time you can increase the voltage, you reduce the current. That's why it's better to run 36 volt motors than 24 volt when running those bigger TMs. For expample, if they made an 82 lb, 12volt motor and it drew 60 amps on max, it would only draw 30 amps in a 24 volt version and 20 amps in a 36 volt. What also comes into play with increased voltage is it takes a smaller wire to deliver the same amount of power with the reduced current, the more current the larger the wire must be, so the motor part of a 36 volt motor can be a lot smaller than the motor on a 12 volt of the same power rating becuase they can use much smaller wire for the internal windings, therefore a smaller armeture.

Less current also reduces internal resistance losses in a ciruit.

That's why power companies deliver the power from the generating plan in 100 of thosands of volts down the main distrabution lines and then drop it with transformers when they get it where it's going. It would take cable the size of box cars to carry the current needed if they tried to use much lower voltage and would have temendous problems with heat and loss at every connection.

Ya know, reading this, I need to start typing everything on a word processor program so it can check spelling and grammar.  Mine sucks when I'm just typing and don't take the time to read what I wrote.

Very informative and I was actually able to follow and comprehend everything you said.  Thanks alot!

i just bought the bigfoot pedal to do the same thing, only my battery setup is 12v. let me know how yours works out

I have two bigfoot switches on my boat and they work great. It has been a while since I put them in, but my recolection is that the big foot should go on the positive line between the trolling motor and battery. Your diagram has it on the negative side. I will look at the boat when I get home tonight and see for sure but I think it should be on the positive.

Beancounter,  The instructions said to use the negative side with the big foot switches

BTW I fixed my problem.  Apparently in makes a difference which  positive and negative leads you attach to which battery that you have rigged in a series.  So I swapped them to what it says in the diagram above.  If you swap those leads (which is the way I actually had it).  you will only get 12 volts and not 24.  Thanks for reminding me why I didn't go to electrician school

T Mike

Triton Mike

You are right, I finally looked at the boat & it is on the negative side. I guess I was having one of those senior moments.

why would u put a switch on the neg side?