89 EZgo Marathon slow up hill... all new parts

[jakerussell08]

I have completely restored my 89 Ezgo marathon. But I felt like it was very slow up hill pull. I know it's a 36v so I shouldn't expect much, but I had a friend just buy the same cart. It had some stuff done years ago to it and it left me in the dust going up hill on the pavement in my neighborhood. My cart works great in the woods and even did great pulling another cart home.

I have brand new batteries

2 gauge wires all around

High speed/ high troque mother (evdrives)

500 amp altrax controller tuned all the way up

Upgraded forward and reverse switch (evdrives)

Largest solenoid

Everything is new so I'm assuming something it not wired right or I not doing something basic.

[HiTechRedNeck]

"Same cart" might have 48v batts or aftermarket motor.

Going to 48v makes all the difference in the world to those carts.
Your 500 amp controller might be able to go to 48v. check specs.

BTW stock motors dont tend to last long at full 500a settings. We usually limit stock motors to 350a.

(Others will chime in on this.... but 500a and hills = heat)

[JohnnieB]

All electric golf carts slow down going uphill. How much they slow down is determined by several factors.

The two major factors are the final drive ratio and how much the voltage being applied to the motor, drops under load.


Being the same year and model, both cart likely have the same differential gear ratio, so the one with the taller tires will slow more going uphill.

What is your tire height? (stock is 18").

The voltage of all lead-acid, wet-cell, deep-cycle batteries drops when amps are drawn from them. The higher the SoC (State of Charge) and the higher the AH capacity, the less they drop per amp drawn.

What is the AH capacity of your batteries? (225AH is the standard for 36V battery packs)
What is the pack voltage about 12 Hours after the charger shuts off? (Should be 38.2V if they are Trojan batteries or clones)
What does voltage drop to while climbing incline?

What is cart speed on level ground?
What is cart speed going uphill?
What is the percent grade or angle of the incline? (chart attached)

[scottyb]

We put hundreds of stock series motors on 500a each year without problems. An increase in voltage will decrease amperage draw which means less weat while producing more torque.
But new 6v batteries already..... so many people do this.

[jakerussell08]

Both carts have same size lift and tires... and both carts have aftermarket motors... my motor is about 6 months old and his is a few years... I know all carts drop speed up hill but mine drops to a almost walking speed...

[cgtech]

I know you said all new cables & everything, but I have to think there is a voltage drop somewhere. Try these 3 tests, then post the results. First, pick which evil Hill will be used for all 3 tests (same hill for all 3 tests). 1- clip volt meter test leads to battery pack main B+ & B-, drive up hill & note voltage at worst speed. 2- repeat test with leads on Motor Controller B+ & B-. 3- repeat test with leads on Motor Controller B+ & M-. If these are all very close to the same, we will have to move on to the f&r & motor.

[JohnnieB]

Also, how new are your new batteries?

If they are not broken in yet, they won't have their rated storage capacity and the less the storage capacity, the more the voltage drop under load.

[jakerussell08]

i will get a volt meter and do some testing and post the results

[jjance]

my motor is about 6 months old

What is the make and model?