Another No-Go Ezgo, here's some numbers...

[JohnnieB]

Originally Posted by labatt50

I guess what I'm asking is: purchase a 500amp or 650amp controller? (going with a 72v controller gives me the option to stay at 48v or convert to higher voltage at a later date).If I'm using this as an off road buggy for hunting, could a 48 or 72v pack ever test the limits of this controller in terms of amp rating? Would I be limited by the controller or put the controller at risk? According to Altrax, this is just bad luck that this happened to the controller (plus it's no longer under warranty). I've only had my current controller (AXE 4855) 3 years, I definitely can't afford to buy a new controller every 3 years. I have a tons of hills around here and can always use more torque, I hate to think is was something I'd did that resulted in the death of my 4855.

Heat kills controllers and controllers with higher amp ratings tend to run cooler when exposed to the same workload. Specifically, it is the motor RPM along with motor type (High-speed, or High-Torque, or a combination thereof) in conjunction with the final drive ration (Tire height and differential gear ratio) and pack voltage, that determines how many amps are drawn. If the amp draw happens to be 500A, then a 500A controller is being operated at or near the upper limit of its heat dissipating ability while a 650A controller is being operated at about 76% of its heat dissipating ability.

A couple things to consider:
1. A motor connected to a higher amp rated controller only produces more torque when the motor is drawing more amps than the lower amp rated controller will pass. You didn't mention which D&D motor you are using, but once it is spinning faster than about 1,500 RPM (Maybe faster - Maybe slower), there is no difference in the amount of torque it produces whether it is connected to a 400A, a 500A, a 600A or a 1,000A controller.

2. Increasing the applied voltage increases the amount of torque a motor produces across the entire RPM spectrum for the motor.

[labatt50]

Originally Posted by JohnnieB

Heat kills controllers and controllers with higher amp ratings tend to run cooler when exposed to the same workload. Specifically, it is the motor RPM along with motor type (High-speed, or High-Torque, or a combination thereof) in conjunction with the final drive ration (Tire height and differential gear ratio) and pack voltage, that determines how many amps are drawn. If the amp draw happens to be 500A, then a 500A controller is being operated at or near the upper limit of its heat dissipating ability while a 650A controller is being operated at about 76% of its heat dissipating ability.

A couple things to consider:
1. A motor connected to a higher amp rated controller only produces more torque when the motor is drawing more amps than the lower amp rated controller will pass. You didn't mention which D&D motor you are using, but once it is spinning faster than about 1,500 RPM (Maybe faster - Maybe slower), there is no difference in the amount of torque it produces whether it is connected to a 400A, a 500A, a 600A or a 1,000A controller.

2. Increasing the applied voltage increases the amount of torque a motor produces across the entire RPM spectrum for the motor.

Ok thanks!

If you'd like to know...

In terms of Motors, I use two:

Around my house hunting - AMD GLO 4001 (7124) "the beast". In this case my cart is just transportation on gravel roads (for cars) to get to farms. I just don't like spending a lot of time on these roads for obvious reasons. There is however long steady hills (3/4 mile-1mile) just going up these hills. Total round trip is usually 4miles or less pending the farm.

I use a D&D ES-5E for Camp weekends. Depending on the season and what we are doing, I switch the motor out from the AMD to the D&D. Truthfully this happens a couple times a year maybe 3times max. I do it because it's just not a place I want to get stuck. As you probably know, his is a pure torque motor, 13mph flat, 7-8mph hills. Nothing seems to stop this thing. Battery life is very good.