Controller upgrade question? 500A or 650A

[firemedic898]

Hey guys, I’m in the process of building my cart right now. I will be upgrading all of the performance parts (motor, controller, cables, ect.) and need help in deciding what controller I need. I plan on using a high torque motor, possible the D&D 4:1 8 peak HP, and an Alltrax controller, due to reviews, performance, durability. Question : With the motor being a “high torque motor”, do I really need the 650A controller? Or should I get a motor with a little less torque/more speed (maybe the 1:1 or ES-52) and add the 650A controller? This way I get more speed from the motor and possibly the same amount if torque.

I will be climbing moderate/high grade hills and encounter long flats with this cart. Another factor to consider is I will have 25” tires. I know this decreases torque and adds top end speed. Pricing is not an issue, I would rather build it right the first time than to come back later. And yes, I’m upgrading everything cables, HD solenoid, HD F/R, ect.

[The Inlet]

Will it be 36v or 48 gear chang?

[firemedic898]

Hi Inlet, I’m not exactly sure what you are asking. I have a 36V system right now. I’m actually contemplating on going to a 48V since I’m changing everything anyway. The problem is my cart’s batteries are about 1.5 years old. I would hate to mix two new batteries in, but I’m not even sure if the 1.5 years would make a difference.

[scottyb]

1.5 yr old batteries may show some decreased performance depending upon several usage factors. If the batteries test good, I would go with 2 new batteries in the bagwell or? and get the full benefit of the D&D 8hp Torque motor... your top end will still be around 23mph but you will be able to pull stumps or any hill you find. Controller wise~ I recommend a 650 or 700 amp unit.

[The Inlet]

Nice 48v we like to use 500amp altrex dcx or 600amp 8.5hp d&d go with 6 8v batts and 4g wirer kit.

[firemedic898]

Thanks for the input guys. Just to clarify, I have a series motor so I think I will need the Alltrax AXE controller.

Scottyb, are you saying that with the 4:1 D&D 8hp high torque motor, 650A, and 48V system that I still get the great torque benefits and top end speeds of 23mph? Will the 48V really give me that much more top end speed? I used the speed conversion formula (the one that factors in motor RPMs, axle ratio, and tire size) and it said with that set up (36V) I would run about 16mph. The formula is pretty accurate because I used it on my stock setup and it was dead on.

[firemedic898]

Hey Scottyb, I did some research on the motor and answered my own question. I used the formula on the motor @ 36v with RPM @ 2780, giving me a top end speed around 17mph. When 48v are applied, the motor’s RPMs are increased to around 3500. Therefore, increasing top end speed to around 22mph. Thanks for the guidance.

As far as the controller, is there REALLY that much torque difference between the 500A and 650A since I’m already using the high torque motor? I spoke with a D&D rep today that said since I’m using the 4:1 motor, I will not see a torque increase between the two controllers. Does anyone have experience with this motor and different controllers?

[ab46501]

I wished now that when I started my build I would have gone 48v. Someday I will probably upgrade to 48.

One thing to consider is that the 650 controller may give you less run time than the 500. That is assuming the motor is capable of pulling over 500 amps.

I don't have as beefy a motor as the D&D, I am running 500 amps on 36v and torque is never an issue for me. With that motor and 48v I think you would be fine at 500 amps.

[firemedic898]

Thanks ab46501, I considered that the 650A may drain my power quicker. I’ve heard good stuff about the 500A delivering enough torque, especially with the high torque 4:1 motor. The major factor is the big 25” tires I’ll have.

[scottyb]

Bigger controller just allows you to draw more amps if you stand on the peddle...