Hi, I want to have 36 volts going through a 24 volt motor. The 36 volt controllers are rated for motors 250-500 watts. My motor (stock honda minimoto sport racer) I think is 150 watts. Will this 36 volt controller work with my motor??? Any help is greatly appreciated.
Thanks soo much NecessaryEvil You've helped me sooo much today! But i'm not convinced that a controller will bump up my amperage. If I have 36V running directly to the motor, the voltage drastically drops in order to give the motor the right amperage. (Watts = Volts + Amperage) How will a controller raise the amperage?
In theory, when you over-volt the motor it should also draw more amps... so using round and very rough math, your 24v 150w motor running at 36v (a 50% increase) should also draw 50% more amps...24v 8amp motor should want to draw 12 amps at 36v. This greatly increases the wattage assuming the batteries can maintain voltage during discharge. A 250-500w controller should be more than enough for your application.
The problem is that my batteries cannot maintan the voltage during the discharge with me (approx 110lbs) riding the pocket bike. This causes the bike to go very slow. How can I fix this?
sorry, I just finished reading the other threads...I'm a slow reader... have you tested if the voltage come up as you ride? because 7Ah batteries should be big enough for a 150w motor, and the voltage on any battery will drop on take-off because of the amps being drawn. At low speeds, the low voltage is no problem but it is supposed to increase as you speed up since the motor draws less amps then...
for example, my kart is a 48v system but at the start it drops to 32v and by the end of my run it gets up to 42v...
Just to try it out, I hooked up three 12 volt batteries in series to make 36 volts. At a dead stop, the voltmeter read 36 volts. When I started moving, the voltage dropped to 11 volts, and when at "full" speed, the voltage was not higher than 12 volts. This did not happen with two 12 volt batteries connected to make 24 volts. The weird thing is that the voltage drastically drops only when the batteries are connected at 36 volts, not 24.
PS for the test, i was not using a controller. The batteries was directly connected through a push button switch to the motor.
Will using a 36 volt controller fix this problem which only occurs at 36 volts?
Ok, gotcha... I have never seen that exact problem before but my guess would be yes, that the 36v controller should work properly. My guess is that possibly with the batteries wired directly through just a switch there is nothing to limit the amps being drawn and that might be why the batteries cant hold the voltage. If any of the components in your setup get hot quickly then that would be a sign of too many amps... other than that, and if the 36v controller does not work then i'm stumped..
Are they all used with the same 2 batteries except for the 36v setup which adds another one? Because it could be the batteries. I would strongly recommend getting a controller because it ups the amps and will make your bike accelerate ALOT faster. Volts = Top speed and Amps = Acceleration basically.
Thank you for your help, but nothing really gets that hot... Also I'm not convinced of getting a 36 volt controller because it will cost me $60 with shipping, and you cannot return them. So from what I understand, the voltage drop occurs because too many amps are being drawn due to nothing restricting them. A controller would limit the amount of amps being drawn, resulting in maintaining a higher voltage??? And yes, I connected three 7Ah 12 volt batteries for the 36 volt setup. Sorry for asking so much, but how does a controller bump up the amps if the battery without the controller cannot deliver them?
My batteries have an innitial current rating of 2.16 amps max. Could this possibly be the problem, since voltage is relative to amperage. So if I got batteries with a higher amperage rating, like car batteries, I should not experience this problem? The only benefit I see in getting a 36 volt controller is that I would be able to start off slow, drawing little voltage, and being able to supply the right amount of amps. As I would speed up, the motor would require less amps, boosting up the voltage... please correct me if I'm wrong. So are car batteries with high amperage rating good enough?
The controller has resistors in it which bumps up the amps. You should be able to get a controller from TNC for less than that unless you live outside of the US. You might be able to get it for cheaper if you get the MX500 controller from Razor.com
I live in Canada, so shipping is expensive... If the controller has resistors, then does it limit the amount of volts to bump up the amps? And if the volts are limited, then the motor doesn't run as fast... from what I understand. If without the controller my batteries are not capable of giving off the required amps, then how is it possible with a controller. Sorry for being skeptical, but I'm uncertain about the purchase of a 36 volt controller... Thanks so much for helping me, especially NecessaryEvil, but could you please answer this question
The voltage drop is because your running a 24v motor on 36v. The best thing you could do is get a 36v controller because it will make the bike accelerate faster, protect the batteries, and allow you to use a controller.
I found this controller: Razor CT-312C1/HB3650TYD4-FS1 Controller/Control Module for MX500 & MX650 (4-Wire Throttle)
It's for the razor mx500/mx650 bikes. Since I'm upgrading my minimoto sport racer to 36V, this controller should work right? It has 4 throttle cables. My twist grip throttle only has 3. I think the fourth wire is for the LED on the newer throttles. Can I leave the fourth wire disconnected? Also, what are the "timing" and "brake (2)" wires for? Can I leave those disconnected aswell?
That controller would work but it is out of stock. Look on TncScooters and get a 30A+ one. The brake wires are suppost to make the motor turn off when you brake. I have no clue what the timing wire is for. If you got the MX500 controller you would not need to hook these wires up.
I found this company Daymak, and their parts and service warehouse is located nearby. You can go there to buy parts, but do you think that their 36 volt controllers will be compatible? I would save $20 on shipping :P
Controller and motor compatability 
Any help is greatly appreciated.
You've helped me sooo much today! But i'm not convinced that a controller will bump up my amperage. If I have 36V running directly to the motor, the voltage drastically drops in order to give the motor the right amperage. (Watts = Volts + Amperage) How will a controller raise the amperage?
