Your 40A controller will get you up to about 25mph.
Then you can short batteries directly into motor for full speed.
Throttle up 40A till full speed then engage a contactor for the full 400A necessary for full power ... hold on to your ass Fred!
I am struggling to understand the concept. Obviously I have never hooked up any DC motor which is rated greater than about 29 amps.
Voltage: 48V DC
Rated Speed: 3000 RPM
Rated Current: 26.7 A
Output: 1000 W
Unite DC MY1020 1000W 48V Brush Motor with Mount Bracket.
That is the most powerful motor I ever hooked up to any controller.
My guess would be that hooking up a 300 amp motor rated at 12 or 24V to a 40 amp controller would result in the controller bursting into flames as the motor would be drawing 300 amps from the battery thru the controller and the controller would catch of fire in less than 20 seconds. What type of voodoo or magic would prevent something like that from happening ?
Is it a capacitor or resister or a diode which prevents such a calamity. If this is correct then the rpm and the voltage of the motor would stay the same and the current would be different with two different controllers but the same battery and motor.
12V @ 375 amp at 2100 rpm = 6 HP or 4500W
That 375 amp motor hooked to a 24V battery and a 40 amp controller would = 960W @ 4200 rpm
The same motor hooked to a 24V battery and a 100 amp controller would = 2400W @ 4200 rpm
Since heat build up in a motor is the main cause of failure the motor is a little more than 1/2 of total power input at 2400W compared to 4500W however the motor is also rated at 2100 rpm and not 4200 rpm so mechanical failure would be caused by rpm and not heat build up. I do not wish to spend that kind of money to blow up a motor. My question then is would the motor hold together at 4200 rpm or not?
The wheel sprocket size would be a 92 tooth custom spoke sprocket from Kings custom sprockets driven by #415 heavy duty chain and a 11 Tooth #410 motor sprocket.The gearing would be for 43 mph.
At 2100 rpm with a 29" wheel and 11T motor sprocket the wheel sprocket = 46T NOT 92T.
I did not wish to go with a 92T custom sprocket so I need to call the manufacturer to find out the rated rpm of the 24V motors which look almost exactly like the 12V motors they sell. and then the motor will NOT be operating at twice the rated rpm.
5S LiPo packs = approx. 20V so a 24V - 2100 rpm motor would be operating less rpm and probably work with a sprocket smaller than a 46 tooth spoke sprocket. A standard 32 tooth bike sprocket which replaces the freewheel is the most logical choice. I would however like to simply run the 6S packs I already own instead of having to spend money on expensive packs.
Please don't give up on me now and keep posting as I want to order one of those motors and that 100 amp controller soon. Thanks.
LC. out.