Problem After New Controller

[DanGoneWild]

Originally Posted by JohnnieB

We've all learned stuff on this forum. I have a halfway decent engineering background and a far better troubleshooting background than most people, but the bulk of what I know about golf carts has been acquired on BGW.

If possible, before sending cart to shop, please record a data log and post it. There are a couple things I'd like to see. For instance motor voltage at top speed, field amps at top speed and some other stuff.

Will do.

[DanGoneWild]

Originally Posted by JohnnieB

We've all learned stuff on this forum. I have a halfway decent engineering background and a far better troubleshooting background than most people, but the bulk of what I know about golf carts has been acquired on BGW.

If possible, before sending cart to shop, please record a data log and post it. There are a couple things I'd like to see. For instance motor voltage at top speed, field amps at top speed and some other stuff.

Ok I think I have attached the log file. First time doing a log too. During this test, I made sure all setting were as pre-set from Alltrax except I moved Max Motoring Armature Amps and Max Motoring Battery Amps down from 500 to 400. Also moved up speed limit rpms from 6000 to 6500. I slowly floored the pedal twice and held it for a short time. Please let me know if you need anything else. Thanks

[JohnnieB]

I was under the impression your cart had a 36V battery pack, but it looks like a 48V pack since the start voltage at first solenoid closure was 50.0voltage.

The controller is applying about 49.1V to the armature when at 100% throttle, but Armature Amps (Motor Current column) only averages 11.0A and peaks at 13.0A, while at full throttle. That ought to be at least 4 or 5 times as many amps (or more), so there is most definitely something with the armature circuit, like brushes or a bad cable.

Also noted the field weakening only went down to 5.3A. I don't have any field weakening data on that motor, but that seems like it is staying a bit high to me. The mapping is partially based on armature amps, so that might change when the motor circuit issue gets fixed.

Nothing abnormal noted other than the above.

[DanGoneWild]

Originally Posted by JohnnieB

I was under the impression your cart had a 36V battery pack, but it looks like a 48V pack since the start voltage at first solenoid closure was 50.0voltage.

The controller is applying about 49.1V to the armature when at 100% throttle, but Armature Amps (Motor Current column) only averages 11.0A and peaks at 13.0A, while at full throttle. That ought to be at least 4 or 5 times as many amps (or more), so there is most definitely something with the armature circuit, like brushes or a bad cable.

Also noted the field weakening only went down to 5.3A. I don't have any field weakening data on that motor, but that seems like it is staying a bit high to me. The mapping is partially based on armature amps, so that might change when the motor circuit issue gets fixed.

Nothing abnormal noted other than the above.

Thanks JohnnieB. Some of that is a little over my head but I'll study on that a while.

BTW, it is a 36 volt pack. I did fully charge them prior to the log. Each of the six batteries showing 6.58 volts just sitting there. Pack showing 38.2. So I have no idea why you're seeing the start voltage as it is. My question would be are those numbers a problem given it's a 36 volt pack? Another weird thing going on with this cart I guess.

By cables, do you mean the cables going from the solenoid/controller to the motor? They appear to be original. The only cables I replaced were from and between the batteries. Think it would be a good idea to replace those as well before I go much further... given the frying of the DCX?

So based on what you see, do you think there's a good chance this motor can be rebuilt or cleaned up if it's indeed the motor?

[JohnnieB]

Originally Posted by DanGoneWild

Thanks JohnnieB. Some of that is a little over my head but I'll study on that a while.

1. BTW, it is a 36 volt pack. I did fully charge them prior to the log. Each of the six batteries showing 6.58 volts just sitting there. Pack showing 38.2. So I have no idea why you're seeing the start voltage as it is. My question would be are those numbers a problem given it's a 36 volt pack? Another weird thing going on with this cart I guess.

2. By cables, do you mean the cables going from the solenoid/controller to the motor? They appear to be original. The only cables I replaced were from and between the batteries. Think it would be a good idea to replace those as well before I go much further... given the frying of the DCX?

3. So based on what you see, do you think there's a good chance this motor can be rebuilt or cleaned up if it's indeed the motor?

1. Connect laptop to XCT and get on monitor screen in Toolkit. The battery voltage is shown just below throttle bar. With your handheld DVM, measure the voltage between the B- and B+ terminals on the XCT. The Battery voltage on the monitor page and on the DVM ought to be the same, or very close to the same. (A few volts less than the battery pack voltage, before solenoid clicks.)

If they are not something is wrong with the XCT's measuring circuits, so none of the reading in the data long can be considered valid.

2. There are a total of ten cables that carry high amps from the batteries to the motor and all ten should be 4Ga or thicker. A bad cable between solenoid and motor or between controller and motor, will reduce performance. More correctly, if defective any one of the 10 high current cables will reduce performance.

3. Have to open it to tell if it can be rebuilt, but even if it isn't the primary source of the low speed problem, servicing a 20 year old motor is a good idea.

[DanGoneWild]

Originally Posted by JohnnieB

1. Connect laptop to XCT and get on monitor screen in Toolkit. The battery voltage is shown just below throttle bar. With your handheld DVM, measure the voltage between the B- and B+ terminals on the XCT. The Battery voltage on the monitor page and on the DVM ought to be the same, or very close to the same. (A few volts less than the battery pack voltage, before solenoid clicks.)

If they are not something is wrong with the XCT's measuring circuits, so none of the reading in the data long can be considered valid.

2. There are a total of ten cables that carry high amps from the batteries to the motor and all ten should be 4Ga or thicker. A bad cable between solenoid and motor or between controller and motor, will reduce performance. More correctly, if defective any one of the 10 high current cables will reduce performance.

3. Have to open it to tell if it can be rebuilt, but even if it isn't the primary source of the low speed problem, servicing a 20 year old motor is a good idea.

Understood on 2. and 3.

On 1. of your post- With key switch off-
controller (B+ to B-) = 37.9
monitor bat voltage = 41.6
again pack reading with handheld = 38.2

With key switch on-
controller = 37.8
monitor = 48.7

Is my brand new controller bad?

[JohnnieB]

Originally Posted by DanGoneWild

Understood on 2. and 3.

On 1. of your post- With key switch off-
controller (B+ to B-) = 37.9
monitor bat voltage = 41.6
again pack reading with handheld = 38.2

With key switch on-
controller = 37.8
monitor = 48.7

Is my brand new controller bad?

The highest voltage possible is the 38.2V at the battery pack.

Until the solenoid contacts close, the voltage between the controller's B- and B+ terminals will read less than the battery pack. 37.9V is lower, but it's usually more on the order of 3V. Might be an issue, but I'm not sure.

I cannot explain there being 41.6V with key OFF and 48.7 with key ON other than something being wrong with controller.

Suggest you contact Alltrax tomorrow morning. https://alltraxinc.com/

[DanGoneWild]

Originally Posted by JohnnieB

The highest voltage possible is the 38.2V at the battery pack.

Until the solenoid contacts close, the voltage between the controller's B- and B+ terminals will read less than the battery pack. 37.9V is lower, but it's usually more on the order of 3V. Might be an issue, but I'm not sure.

I cannot explain there being 41.6V with key OFF and 48.7 with key ON other than something being wrong with controller.

Suggest you contact Alltrax tomorrow morning. https://alltraxinc.com/

thanks man. Will do.