Some cable testing on sizes 4g to 2g

[JohnnieB]

Originally Posted by speedgolfer

I don't know none of them fancy terms just the test i did and what i got was better
what is bottle necking in the current loop
the cart used to be faster with this same set up but over the years it has slowed down about 3 mph, stock controler, 36 volt battery set up, 18.5 tall tires

Originally Posted by speedgolfer

yes it always went around 18 MPH but has gotten slower over the years the cart has 1000's of miles on it everything is stock from new i have replaced batterys and cables and a micro switch thats it

Sorry about them fancy terms.
bigpoppi explained bottlenecks pretty well.

Attached is a drawing of the current path in a cart with a series wound motor.
I call it a high current loop because the current (amps) start at one of the battery pack's main terminals, flows through all the cables and components to the other main terminal on the battery pack. Then it flows through the batteries and cables within the battery pack back to the same main terminal it started from, completing the circle, or loop.

The purple line is a four lane highway and if it narrows down to fewer lanes anywhere along its length, a traffic jam will occur and some drivers (amps) will find alternate routes and not pass through the motor like they are supposed to.

Basically, the total current passes through everything, so each cable, connection and set of contacts has the be capable of passing as many amps as all the others, or the cart loses performance.

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Mathematically, around 15MPH is all you should be getting at 36V with a stock differential gears and 18.5" tires, but it used to go faster.
My guess is your cart has a high speed motor.

Plug your serial number in here and it might tell you if it came from the factory that way. http://www.shopezgo.com/customer-ser...ialNumber.html

If it does have the high speed motor, the speed that has been lost over time, may be due to something like bad contacts in the F/R switch, or solenoid contacts, or worn out brushes in the motor, or the throttle (ITS) isn't telling the controller to turn on all the way.

Any component getting hot (or very warm) needs to be replaced, but the throttle will have to be checked out with a voltmeter.

With a little troubleshooting, you can probably find the lost 3MPH.

[speedgolfer]

The motor stays cool solinod is'nt hot or any of the cables F/R switch is clean and not burndt but i have not had the motor checked out, like i said the cat has 1000's of miles on it
i will have to punch in the serial # once thu
thanks for all the help
Mike

[JohnnieB]

Originally Posted by scottyb

It looks like we could safely say there was a 25% reduction in speed loss under load but ... I wonder what that would equate to in actual amperage delivery?

Assuming the total high current cable length is 25' and the controller passes 275A, 2Ga cables will deliver 174W more power to the motor than 4Ga.
(Amps times Amps times Ohms = Watts)
At 38.2V (100% SoC), that equates to about 4.56A.
(Watts divided by Volts = Amps)

But amps loss will become greater as battery pack discharges.
100% = 4.563A
80% = 4.650A
60% = 4.696A

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It should be noted that the difference in voltage drop across the cables is only a bit over 0.6V (0.634V).

Bottom is it doesn't take much resistance to steal a lot of performance.