Help please....Controller getting hot on EZGO TXT 48v

[Moonstalker]

Ok I finally forked out the cash to do some upgrades to my hunting cart and it still isn't happy! I'll list the details below, any advice is appreciated! Thanks in advance

1999 EZGO txt series 48v...new 6/8v Trojans
Lifted with 24"dirt devils
upgrades- 400a solenoid, hd fnr switch, 2 ga wiring throughout, BU500L controller

The latest upgrade I did was the motor, I had a local cart shop put in a AMD #7122 motor and it made the cart fly(28+mph) which was cool but I primarily use it for hunting where I do more low speed crawling around than anything. So the first hunting trip after installing the new motor my controller got real hot at the end of a 4-5 mile loop around the ranch. I asked around a few of my buds that have electric hunting carts and they thought the new motor I installed was labeled as a "high speed" and not designed for "creeping" around and any climbing. So I did a little research on the AMD motors and sure enough the 7122 is labeled as a high speed, so I called up the guy that I had install it and who had recommended it and told him I didn't think it was going to work for my hunting applications and he got back with me and said he would trade it out for one labeled as a high torque that should work fine....sooo fast forwarding he swapped the motor out for a AMD #7124, which after reading up on it is labeled as a high torque and rated at 11.4HP @ 2300RPM for 48v and says its comparable to the Beast which I've heard good things about. I picked it back up last week and was all excited about the change and hoping I'm finally going to get to enjoy my cart for a good while, but NO.... I take it to the ranch again this weekend and the same thing happens, controller gets hot and actually gave out for a while but seemed ok after cooling off. Nothing else feels hot. The new motor seemed to have better torque but not just head jerking and I am still getting speeds of 26+ on flat ground. Thanks for listening and I'm really hoping someone can help.

[yurtle]

Dunno anything about your controller, but if you can connect a laptop to it, you may be able to limit the amps to less than 400. There may be other options like pedal up and pedal down, which control inrush, which also equals heat.

I have a 500 amp controller with an ammeter, and even on the steepest hill, I rarely see 400 amps for more than a few seconds.

[yurtle]

Also, while it may seem a waste to limit a 400 amp controller to 300, consider that you would be running it at 75%, rather than a 300 amp controller running at 100%, and if heat is causing you to shut down, the extra headroom will have still been worth it.

[JohnnieB]

Ditto on what yurtle said, plus:

The 24" tall tires altered the final drive ratio and you are getting about 25% more speed and 25% less torque than you would with stock height (18") tires.

If you replaced the differential gears with a numerically higher ones, you would reduce the top speed and increase the torque closer to what you are looking for.

I'm more into the electrical stuff than mechanical stuff, but stock differential gears are 12.44:1, so a 17:1 ratio, if such and animal is available, would return most of the torques lost by the tall tires.

Smaller tires would also be a step in that direction.

[scottyb]

The torque motor you are looking for would limit top speed to about 15mph.
As mentioned workhorse gears would reduce a little of the torque loss from the 24 inch tires.
Ask your supplier for a lower RPM motor.

[Moonstalker]

Thanks for the replies guys, here's a pic of my controller. I can't find any port were I can plug something in so I assume it is not programmable?

I hear what y'all are saying on the gears and tires but I am perfectly fine with how it handles now for my purposes, except for the hot controller part of course! So question, could I go overkill on a bigger controller to make it happy without messing with the gears or tires? And if so, please suggest one. Thanks!
ImageUploadedByTapatalk1353941387.695074.jpg

[KactusKiller]

Just a little added info, With the exact same setup minus the new motor(had a stock motor) he did not have the heat issue that he is having now. He ran this setup for at least a year. He converted to 48vlt and the new motor on this last upgrade. Tires have been on this cart since he bought it, it was bone stock 36 vlt. with lift and tires.

[scottyb]

Clearly the motor draw is the source of the problem. Try running the stock motor again, with the 48v.

[Moonstalker]

Yikes, I don't have the stock motor anymore. When I upgraded the motor I didn't even think about asking my guy for my old stock motor back, I guess I didn't think I would get much for it or need it for anything. I'm going to call him on all of this today but please let me know if any more thoughts. thanks

[Dela]

ouch - Always keep stock parts, sell 'em on the bay!