Ezgo Power Problems

[Snowman2]

Sounds great. I am in the process of getting all that you suggested done. Thanks again,

Brad

[Snowman2]

Once again thank you, Scotty and Johonnie, I got my cart back today !! The GE 500 amp controller was put in and it runs GREAT !!!... It is enough power to take off fast and have the input needed when the pedal is pushed.

I lost a little on the top end. The shop did not put in a heavy duty solenoid, they put a 100 amp with a peak 400.

Question, Should I replace the solenoid with a heavy duty one ? Will it help with the top speed or just help with the current flow ?

I know I am splitting hairs, but I am just curious. I lost about 1.5 on the top end for some reason.

Will a heavy duty solenoid help with the issue or is just a safety issue for the current/amp flow ?

P.S. I checked the wires and I have 4 gauge throughout the entire cart.

Thanks,

Brad

[JohnnieB]

Originally Posted by Snowman2

..............I know I am splitting hairs, but I am just curious. I lost about 1.5 on the top end for some reason..............

I split so many hairs in my youth that I've almost ran out of them and now have to wear a tinfoil hat or get a sunburn on the exposed scalp.

I'm not familiar with GE controllers, but I am fairly well acquainted with Ohm's, Kirchhoff's, Peukert's and the other, lesser known, laws that govern how electrical things work.

With an unlimited current source, a series wound motor will accelerate until the Back EMF (Electromotive Force) equals the applied voltage. (Or self-destructs)
Therefore: Speed is directly proportional to Voltage in series carts.

Due to electrolyte stratification, the internal resistance of a lead-acid cell increases during discharge.
Therefore: The terminal voltage of a lead-acid battery decreases under load. The greater the load (current draw) the more the voltage drops.

Current passing through a resistance develops a voltage across the resistance.
Therefore: The greater the current flow through a resistance, the greater the voltage drop across it.

Bottom line: Unless the GE controller isn't turning on fully (IE: PWM output to motor isn't reaching a 100% duty cycle); The increased current draw from the battery pack is depressing its terminal voltage more than before, or the increased current flow through the previous existing resistance in the high current cables, connections and components is dropping more voltage than before. Or a subtle combination of the three.

Think of the high current drive circuit as a garden hose with some kinks in it.
Using a small nozzle, the kinks weren't causing any noticeable problem, but when a larger nozzle was installed, they became more apparent.

Any cable, component or connection that is hot after a few minutes of hard use, should be repaired/replaced.
Any cable, component or connection that has any voltage drop across it other than the motor windings, should be repaired/replaced.
Break out the DVM, attach it across the likely suspects and monitor it while driving.
The goal is to eliminate all the undesired resistance and make the circuit as efficient as possible.

Personally, I think the 100A (400A Peak) solenoid is a little lightweight for a 500A (Peak) controller and tall tires, but I might be wrong.

Also, you can most likely get a little more top speed if you accelerate to it slower rather than quicker.
Less peak current draw from the battery pack while accelerating means less terminal voltage depression and voltage = speed.

Hope the helps.

------------- Added

Check the throttle input to the controller.
IT may not be being told to turn on fully.

[Snowman2]

Once again, Thank you. I will check what you have pointed out and go from there. Your replies are a HUGE help and make me understand more about how the systems works.

Thanks again,

Brad