Overheating Alltrax XCT400 advise

[nobodeuno]

Hi everyone,

I am dealing with an overheating Alltrax XCT400. I have a 2008 48v ClubCar with stock motor but I upgraded to an XCT400 controller. I experienced some overheating in the hottest part of the summer and thought it was just because of the hot weather. So I added a fan to the controller and that seemed to help a bit. Now that I'm starting to get the golf cart out more I realize it just delayed the overheating. I now have 23" tires and I've installed new batteries and new 4ga battery cables. I do have some pretty major hills in my neighborhood so that could also be aggravating things further.

When going up the hills the cart seems to be making a sort of high pitch whine that I didn't notice quite as much as I did before. I think this is coming from the motor...maybe this is an indication of the motor being the issue?

After speaking with Alltrax they offered for me to send in the controller to see if it has an issue. They said it is either the controller, the motor or the cables. I'm wondering if I should try upgrading to 2ga batter cables. I am still using the same stock cables to the motor (they appear to be 4ga I think) so I figured they were fine but maybe I should also swap those out before taking the controller out.

Also in terms of the motor...how does one figure out if that is an issue. I tried measuring the temp. of the wires with a digital thermometer and after a short drive the cables coming off M- is about 160+F but it seems to be around the same temp. at the motor as well. When it goes into thermal shut down it is close to 200+F

Looking for advice on whether I should just pull the controller and ship it back for testing or if I would be better off purchasing some 2GA cables for the battery and from motor to controller. Then if that doesn't work look at either the motor or sending controller back. Although Alltrax said that the 4ga wires I are plenty for my configuration and that I should not be seeing that sort of heat...

Any thoughts or recommendations on what my next steps should be?

[ojo]

Nobody... I'd guess the tall tires and the hills are the problem

[nobodeuno]

It was happening before I installed the tires. And when I spoke with AllTrax they didn’t seem to think the hills or the tires should be an issue especially since I had a fan. said it had to be an issue with the controller, wires or motor. Just not sure which is most likely. I guess I will start with the cheapest one wires then go from there.

[ojo]

Ok, but with that tall tires you get lost of a significant amount of torque. Going uphill, you'll need much torque. Upgrading the battery/motor cables doesn't hurt, but controller/motor will still generate some heat.

[scottyb]

Collect a monitor file and post it here.
Stop guessing and get a live controller report on battery and motor activity.
This is one of the best attributes of the controller you have.
Software and user manual is here > https://alltraxinc.com/alltrax-tool-kit/

[nobodeuno]

Ok here is my live controller report. I ran it up and down a hill twice. It was already pretty warm from a short ride right before this but it got pretty hot to where I started smelling something burning so I parked it...

Not really sure what I'm looking for but I think something might be wrong with the motor because it just doesn't feel right. Let me know what you think.

[Fairtax4me]

How old are your batteries?

What brand and model# are they?

[nobodeuno]

They are about 8 months old and they are us battery 8vgcxc

The batteries were charged last night but I took about a 15min ride before I took the logged drive so they were not fully charged but close to it.

[scottyb]

I viewed the file. The motor amperage draw is higher than normal for a stock motor. I think you need a motor. I would choose a purpose built motor for big tires and hills. A4 would be the my choice or an A2 would be okay too.

[Fairtax4me]

Originally Posted by nobodeuno

They are about 8 months old and they are us battery 8vgcxc

The batteries were charged last night but I took about a 15min ride before I took the logged drive so they were not fully charged but close to it.

OK, what charger are you using?

Seeing battery voltage dropping into the low 40v to 39v range seems like either the batteries can't keep up, or you have a major issue with the motor pulling far more amps than it should be. Even with a 500A controller and an upgraded motor they shouldn't drop that much.
Since batteries are the life-support of the cart I would really want to make sure those are charging properly first before buying anything else.
After a full charge US battery usually recommends that the pack should be sitting around 51.2v 12 hours after the charger finishes. At the very least you should not be below 50.9 12 hours after charge. Your log starts out at 50.4 which show the pack is already 15 to 20% discharged at that point. Can't really go purely by voltage for SOC, but since the voltage is dropping so much during operation the batteries and charger certainly need to be checked into IMO. Check the water levels and make sure they are correct, and if you have s smart charger make sure it is set to the correct algorithm for US battery. I can offer some other suggestions for testing the charger once I know which charger you have.


Motor amperage will be higher if battery voltage is lower. Voltage and amperage are inverse of each other, when amp draw is high voltage will be lower. When voltage is higher, amp draw will be lower. Higher amp draw creates heat, which only causes more issues.
Generally when a motor has a problem the amp draw will be higher, but the only way to tell that is to be sure the battery pack is reaching a 100% full state of charge first.

If there is a motor issue it might be worn or damaged brushes, or a shorted coil in the armature. Either one can be checked with a multimeter set to check continuity.
With the cart in Tow mode, pack Negative disconnected, and one rear wheel jack up of the ground, remove one of the A terminal cables on the motor (whichever is easier to get to). Be sure to hold the lower nut with a wrench to keep the stud from twisting.
Check for continuity from A post to A post, it should have continuity. Then spin the wheel that's off the ground so it makes the motor spin while checking continuity and it should be consistent. If it comes and goes, or there is no continuity the brushes are worn or stuck and the motor needs to be removed for repair or replacement.

Also check for continuity from either A post to the motor case. There should be No continuity.
If there is continuity to the case, the armature is shorted and the motor needs to be replaced.