97 ez go txt converted to 48 volts going slow .

[97ezgotxt48]

[QUOTE=JohnnieB;1648064]The problem is the expectation of a 48V motor powered by a 48V battery pack spinning as fast as a 36V motor powered by a 48V battery pack.

So did I screw up getting a 48 volt motor. Should I have bought a 36volt motor instead? Im just wanting 20mph sustained speeds and to able to haul 4 folks without losing substantial speed going up hills. I’m running 13ish mph on flat ground and 8-9 mph on hills just me 180lbs.

[JohnnieB]

Originally Posted by 97ezgotxt48

It is a series cart

alltrax controller says resting battery voltage is 34 volts. Batteries were charged about 12 hours ago. With the throttle down it is hovering between 48ish-50ish volts

The pedal up battery voltage reported by the SR ought to be a few volts less than pack voltage, it is the charge being maintained on the filter capacitors through the pre-charge resistor. When the pedal is pushed just far enough to make solenoid click, the battery pack voltage, as measured between the controller's B- and B+ terminals, is shown.

34V is mighty low for a pedal up voltage.

[97ezgotxt48]

[QUOTE=JohnnieB
34V is mighty low for a pedal up voltage.[/QUOTE]

What would cause such low voltage?

[JohnnieB]

Originally Posted by 97ezgotxt48

So did I screw up getting a 48 volt motor. Should I have bought a 36volt motor instead? Im just wanting 20mph sustained speeds and to able to haul 4 folks without losing substantial speed going up hills. I’m running 13ish mph on flat ground and 8-9 mph on hills just me 180lbs.

The screw-up was not doing enough research before buying a motor.

Nearly all traction motors that are used in golf carts will run from about 36V, or less, up to 48V, or more, so the trick was to find out where you were with a stock (36V) motor running at 48V and figure out what was needed to get you to where you want to be.

20 MPH is only about 4650RPM with stock tires (18" tall) and stock gears (12.44:1) in the differential. Admiral, AMD, D&D, EMI, Plumb Quick and most other cart motor manufacturers have motors that will do that at 48V. If your tires are a lot taller than stock, you'll most likely need a torque motor rather than a speed motor to make up for the torque loss cause be the taller tires. Also, low pressure tires take more torque to turn than standard pressure tires.

Series drive systems slow more going uphill than Sepex and AC drives, but they all slow down some. The heavier the load, the more the cart slows. Carts will stock (or smaller) tires slow less than carts with tall tires. Carts with torque motors slow less than carts with speed motors, but high-speed/high-torque motors do exist, so there are exceptions.

What is the tire height?
What is the max inflation pressure?
What did it do with the stock motor?
What is her make/model of the 48V motor?

[97ezgotxt48]

I actually did quite a bit of research before I jumped into this project picking out specific components based on reviews and recommendations I had found. I however am not an expert. I researched wires,solenoids,batteries, switches, controllers and motors before I started. I had narrowed down my motor choices to d$d and plum quick. I went with plum quick because once I spoke with Robbie on the phone it made it sounded like their 48v black widow motor would do what I was needing to do based on his feedback and specs online. I know series carts lose a little speed on hills. I’m just not as impressed with the final product and I’m not sure that there is not something I am missing or a specific component not working right that is causing an issue.

Stock tires
30 psi
Plum quick black widow motor
Trojan 8v batteries
Alltrax 48600 controller

[JohnnieB]

You have a SR48600, correct?

Do you get any error codes?

Does the LED go to yellow (amber) when pedal is on floor?

Attach a screen capture of the controller settings in Toolkit.

According to the PQ Specs, the 48V Black Widow ought to propel a two seater series drive cart at 18-20 MPH on stock height tires and a 48V battery pack. Have you contacted PQ and asked why your motor isn't performing to specs?

[woffoja]

I don't know what the answer is to your question, but for comparison, I upgraded my 2000 EZGO TXT PDS cart from 36v to 48v with the AllTrax controller and stock motor and get 28-29MPH. I do have 23" tires on the cart and they're a bit overinflated, but still, I'm very happy with the performance (until the motor burns out �� )

[97ezgotxt48]

Originally Posted by woffoja

I don't know what the answer is to your question, but for comparison, I upgraded my 2000 EZGO TXT PDS cart from 36v to 48v with the AllTrax controller and stock motor and get 28-29MPH. I do have 23" tires on the cart and they're a bit overinflated, but still, I'm very happy with the performance (until the motor burns out �� )

Thanks for the comparison. I’m checking the field maps with alltrax this afternoon to make sure they are correct for my motor and controller combo.

[JohnnieB]

Originally Posted by 97ezgotxt48

Thanks for the comparison. I’m checking the field maps with alltrax this afternoon to make sure they are correct for my motor and controller combo.

woffoja has a PDS (sepex) and you said you have a Series drive. Series motors don't have field maps.

[97ezgotxt48]

ell I figured out what the problem was. I had an alltrax speed controller hooked up but had the setting set to user 1 switch mode with the controller turned off. I had assumed that this would negate any input coming from the speed switch.....I was wrong. After turning the cart to the alltrax speed controller setting on it will now lift the front of the cart off the ground and roll at 20mph with stock tires. Problem solved.