36v EZ-GO TXT Battery Cable Length

[v UNO v]

Originally Posted by Sir Nuke

for all intensive purposes, as long as the strand count of the cable is the same, you will be good.

It sound like i need to start counting because it was given to me and i have no idea what the stand count is.

[Sir Nuke]

Originally Posted by v UNO v

It sound like i need to start counting because it was given to me and i have no idea what the stand count is.

lol well if you look at the end of the cable.....you will see all the copper STRANDS (wires)

if there is print on the cover of the cable, it MAY tell you, or at least use google to find out exactly what you have.

ScottyB uses either 400 or 600 strand count, depending on which size cable he is making.....I am sure if you ask him he will tell you what count he uses for his 2 ga. cables.

[JohnnieB]

Originally Posted by Thatsme?

By JohnnieB
All cables have resistance, so all cables have a power loss (Amps passing through resistance produce heat, which is power that cannot be converted to motion by the motor) and a 2Ga cable has 255% less power loss than a 6Ga cable and 161% less power loss than a 4Ga cable.
JohnnieB would you expand on this to theoretical amp difference?

I haven't done my cables yet. I doubt 20ft is enough for all the cables. 13 I think but I don't remember if he had a series cart.

It's just Ohm's laws and number crunching.

The battery, controller, cables and motor are all in series, so the same number of Amps are passing through all of them. (There is a slight exception with two of the cables feeding a sepex motors, but for practical purposes, they are the same.)

Basically, the number of Amps flowing is determined by the motor and is limited by the controller and the battery's ability to produce them. The cables resistance to current flow (Amps) in is minor influence. However, it does influence the amount of power (Watts) transferred from the battery to the motor.

Work done is measured in Watt-Hours (Wh)and the rate of transfer or conversion is measured in Watts (W).

For work to be done, Watts (Volts X Amps = Watts) are converted to heat or motion (or some other form of energy). When Amps pass through resistance they convert Watts into Heat and when they pass through a motor they convert Watts into motion (Torque and RPM).

If there is 300A of current flowing through a 36V cart's high current circuit, there are 10,800W available for conversion. (V*A=W)

If there is 20' of 6Ga cable there is 0.0079020 ohms of resistance, so 711W (I^2 * R =W) are converted to heat and the motor only has 10,089W to convert to motion. (93% efficiency of the power delivery system.)

With 20' of 2Ga cable there is 0.0031260 ohms of resistance, so 281W are converted to heat and the motor has 10,519W to convert to motion. (97% efficiency of the power delivery system.)

711/281=2.53, so the 2Ga cables looses 253% less power. (I used 100A when I stated 255% less loss)

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Since applied Voltage determines motor RPM, the voltage drop across the cable resistance does reduce the cart's top speed, but at high RPM the motor current is low, so the voltage drop isn't much.
At 50A the drop would be 0.395V for 6Ga and 0.156V for 2Ga.

However, going from a bad (high resistance) set of cables to a good set of cables may have a noticeable speed increase. (Not true for PDS carts because controller limits motor RPM)

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Hopefully, this clarifies. There are many of other factors involved, so I tried to keep it to a bare minimum.

[Thatsme?]

Thats GREAT JohnnieB.

I understand that perspective better than the other way.
I like the way you explain things.

[v UNO v]

Originally Posted by Sir Nuke

lol well if you look at the end of the cable.....you will see all the copper STRANDS (wires)

if there is print on the cover of the cable, it MAY tell you, or at least use google to find out exactly what you have.

ScottyB uses either 400 or 600 strand count, depending on which size cable he is making.....I am sure if you ask him he will tell you what count he uses for his 2 ga. cables.

Ill have to look, thank you for that.

Originally Posted by JohnnieB

However, going from a bad (high resistance) set of cables to a good set of cables may have a noticeable speed increase. (Not true for PDS carts because controller limits motor RPM)

Im sure my cables could be replaced so im sure it will help me across the board.

My only question is, i had the 20 ft of cable just sitting in a cabinet in garage. The have never been used since they have been cut, do i have to worry about these cables being bad like SIR NUKE said?? If so how do i tell that they are bad?

[yurtle]

Originally Posted by v UNO v

I have 20 ft of 2 guage welding cable and i was going to make new battery cables. It seems to me, the current lenght of my cable is in unnecessary and I could save about 1-2 feet of cable if I take the current "S" shape they have out of them and did shorter straighter cables.


My questions are;

• Does it matter what length the cables are?
  
• Is there a minimum or standard lenght for these cables?
  
• Should i match the current length of all my cable or can i shorten them down some?

All I know not to block the battery covers but that is about it.

Thank you in advance to everyone because any information would be helpful.

Battery interconnects can be shortened "some". A little looseness doesn't hurt. However, don't skimp on the cables that go to the motor. Everything besides the motor is stationary, relative to each other, however, the motor moves up and down, relative to the buggy, and needs enough slack to keep from rubbing, or worse, breaking. Technically the motor/rear-end are stationary relative to the road, and the buggy bounces up and down over bumps.

[yurtle]

Originally Posted by v UNO v

My only question is, i had the 20 ft of cable just sitting in a cabinet in garage. The have never been used since they have been cut, do i have to worry about these cables being bad like SIR NUKE said?? If so how do i tell that they are bad?

I don't know how old the cable is, but I'd expect you can flex it and visually see if the insulation breaks. I have an old buzz-box that's so old it has copper windings, and the cable looks to be in great shape, and it's been physically abused, being dragged around on concrete floors.

[v UNO v]

Originally Posted by yurtle

However, don't skimp on the cables that go to the motor. Everything besides the motor is stationary, relative to each other, however, the motor moves up and down, relative to the buggy, and needs enough slack to keep from rubbing, or worse, breaking.

Thank you for the heads up. I will keep that in mind for when i make them.

Originally Posted by yurtle

I don't know how old the cable is, but I'd expect you can flex it and visually see if the insulation breaks. I have an old buzz-box that's so old it has copper windings, and the cable looks to be in great shape, and it's been physically abused, being dragged around on concrete floors.

The insulations looks good. I was bending it last night and it feels and looks brand new. If thats what i should be worried about i think im in the clear.

[v UNO v]

Here is a picture of how my cart is currently wire (how it was when i bought it.) I thik im going to take SIR NUKE's set up and make them the same length but look them like his. IM not a big fan of the "S" shape it has now.

Also this is all the numbers off the weldind cable im going to use. Im not sure of the strand count but maybe someone can tell just by looking at the numbers?

[tteckster]

2/0 (00AWG) cable is better than 2AWG cable. Resistance is less also, 0.00007793