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Positive ground

Posted: Tue Feb 06, 2007 3:07 pm
by Mike's 49 Cub
Thought I better ask before I screw something up. I have positive ground on my battery. When I hook up my charger I disconnect the battery cables then hook charger up as normal.. red - positive and black negative. I really don't understand this "positive" ground stuff. On my garden tractor I leave the battery charger hooked up while I try starting it. If I leave the battery cables hooked up on the Cub and hooked my battery charger to it red/positive and black /negitive am I looking at having some trouble if I try starting it while hooked up and would it be hooked up properly ?? Positive ground-- I don't know !!!!!!!!!!! Help Mr. Wizard !!!!!!

Posted: Tue Feb 06, 2007 3:17 pm
by Matt Kirsch
As long as you connect positive to positive and negative to negative, there will be no trouble at all. Polarity is all that is important.

The only difference between positive and negative ground is the direction the electricity flows. Electrical parts don't care whether a wire brings the juice or a huge chunk of cast metal does. All they care about is positive-to-positive, and negative-to-negative.

Posted: Tue Feb 06, 2007 3:20 pm
by Bus Driver
Set the charger for the correct voltage. Connect the red charger clamp to the positive post of the battery ( or the battery terminal on the cable installed on the battery). Connect the black charger clamp to the negative post or terminal. Plug the charger into the premises power outlet. Battery charging with the battery properly connected is not a problem. Unplug the charger from the power source first before removing the clamps from the battery.

Posted: Tue Feb 06, 2007 3:36 pm
by Bigdog
I think it's important that people understand that neither the pos or neg lead of a battery charger is "ground" It only becomes "grounded" when attached to the battery terminal that is attached to vehicle ground.
Battery chargers are always connected positive to positive and negative to negative.
That being said, I also feel that older standard battery chargers - those without current limiting protection - should be disconnected before an attempt is made to start the vehicle. During the start cycle, a lot of current is demanded by the circuit, if the battery cannot supply it, the charger will try to and if there is no current limit protection the charger can be damaged.

Posted: Tue Feb 06, 2007 4:14 pm
by grumpy
Big Dog Thank you. :) :) I have been telling a friend that technically(sp) a battery has no real ground terminal.It's up to you which post you want to be the ground. :lol: :lol: Dave

Posted: Tue Feb 06, 2007 4:38 pm
by CTdave
So with all this being said, If I were bare foot, standing in a puddle and I touch anything metal on the tractor, I could get a 6 volt tingler? I doubt it would hurt considering the feeling of 110ac pulsing up your arm :shock: but wouldn't I get some sort of charge? What about an impliment in wet ground?

Posted: Tue Feb 06, 2007 4:50 pm
by Bigdog
Dave - first of all - 6 volts is not enough potential to push a current flow through your body. (which is what would have to happen for you to feel a tingle)
Secondly, the tractor chassis is in no way at a voltage potential with an earth ground. The battery has one terminal attached to the tractor chassis and the other terminal is supplying voltage potential to various circuits which all return back to the battery through the chassis.
Even standing barefoot in wet ground there is no current path through you to anywhere since the tractor chassis is not charged in relation to earth. Standing barefoot in a puddle can be lethal if you touch a live electric (AC power line) circuit since the vast majority of common power sources are connected to an earth ground. (There are some AC power circuits that are isolated from ground but most are not.)

Posted: Tue Feb 06, 2007 4:56 pm
by CTdave
The only thing I know about electricity is to stay far away from it :shock: :shock: (yes, there will be electrical questions coming from me soon :?

Posted: Tue Feb 06, 2007 5:04 pm
by Jim Becker
Bigdog wrote:the tractor chassis is in no way at a voltage potential with an earth ground. The battery has one terminal attached to the tractor chassis and the other terminal is supplying voltage potential to various circuits which all return back to the battery through the chassis.
Even standing barefoot in wet ground there is no current path through you to anywhere since the tractor chassis is not charged in relation to earth.

Otherwise you would get a big spark when you use a chain to pull a 6v positive ground tractor with a 12v negative ground truck.

Posted: Tue Feb 06, 2007 5:33 pm
by Bigdog
Jim Becker wrote:Otherwise you would get a big spark when you use a chain to pull a 6v positive ground tractor with a 12v negative ground truck.


Or vice - versa - like pulling a Stuck Chevy with Donny's Ford??? :D :D :D :D

Posted: Tue Feb 06, 2007 6:22 pm
by Mike's 49 Cub
I should look into taking a basic electric /electroinic's class somewhere. I also have a meter for testing circuits .,ect..... Really don't know how to use it other than testing an outlet to see if it has power. If I knew how to use it properly I know I would be amazed at how much more I could get done without having to go to someone else and ask . Oh well -- can't do it all .. it's nice to have people to ask who are willing and able to help out. Thank's . Mike

Posted: Tue Feb 06, 2007 7:19 pm
by Gary Dotson
Big Dog, that was a nice job explaining something many of us older folks just take for granted.

Posted: Tue Feb 06, 2007 7:37 pm
by Kit Sumner
I'm with you, Mike. I have a multimeter that I use for only basic info. as in voltage reading or continuity checks, but basically this instrument could do a lot more in educated hands. I just know I'm going to be asking questions about my Cub's electrical system that I really should be able to determine myself. You've given me a great idea - I'm going to take my multimeter to Cecil's Cub minifest the 17th and get some hands on instruction. :) :) Kit

Posted: Wed Feb 07, 2007 12:33 am
by grumpy
Point well taken from Big Dog However when the tractor is running and someone :oops: is dumb enough to pull a plug wire with their bare hand you WILL feel that "tingle" Don't ask :!: :!: Grump

Posted: Wed Feb 07, 2007 2:46 am
by FCUBMAN
grumpy wrote:Point well taken from Big Dog However when the tractor is running and someone :oops: is dumb enough to pull a plug wire with their bare hand you WILL feel that "tingle" Don't ask :!: :!: Grump


Well, that is a bit more than six volts :shock: :shock: :shock:
Love your tagline!
Brian