motor retarding

[kevinmccune]

I found out if you touch the pole wires together on a DDmotor you get a retarding effect, will this harm the motor or controller?

 

[AHicks]

Thinking it would. It's going to overheat and cook itself. The faster it's turning the quicker that will happen.

 

[kevinmccune]

Thinking it would. It's going to overheat and cook itself. The faster it's turning the quicker that will happen.

Yes, I believe you are correct, the counter EMF would burn it up, now perhaps if it were hooked to a" sink" or load. to consume the current, there would definitely be heat generated.

 

[AHicks]

Yes, I believe you are correct, the counter EMF would burn it up, now perhaps if it were hooked to a" sink" or load. to consume the current, there would definitely be heat generated.

Check out how a diesel locomotive does this (dynamic braking)....

 

[harryS]

A good controller does that, routing the motor EMF power to the battery when the brake contacts close. I've never investigated the details, as a DD motor doesn't suit my riding style.

I'm sure it doesn't hurt the controller as it was designed for it. And big DD motors probably see more heat generated powering the bike up a hill. It could possibly generate an overvoltage to the battery, and the controller would have to sense that and stop regen.

 

[AHicks]

A good controller does that, routing the motor EMF power to the battery when the brake contacts close. I've never investigated the details, as a DD motor doesn't suit my riding style.

I'm sure it doesn't hurt the controller as it was designed for it. And big DD motors probably see more heat generated powering the bike up a hill. It could possibly generate an overvoltage to the battery, and the controller would have to sense that and stop regen.

Therein lies the problem. For instance, if somebody with a large down hill run very near their house, leaves their house with a fully charged battery, and goes down with regen engaged (dragging brakes slightly) the BMS senses the charge coming in via regen, shuts down the incomimg power, and stuff doesn't always go to plan from there. You get into a pretty grey area with an occasional smoked controller.

 

[kevinmccune]

Therein lies the problem. For instance, if somebody with a large down hill run very near their house, leaves their house with a fully charged battery, and goes down with regen engaged (dragging brakes slightly) the BMS senses the charge coming in via regen, shuts down the incomimg power, and stuff doesn't always go to plan from there. You get into a pretty grey area with an occasional smoked controller.

need a relay and a shunt into a spare battery ,light or resistor( perhaps a small propellor running in reverse mode) Rube Goldberg or the Nutty professor lives! Bikes with regen are funny, Eahora is aggressive and the Yamee is not quite as aggressive ( for the money the "Yamee was") quite well equipped My new build uses a 1000 watt DD motor it remains to be seen if the controller regens or not, no kits were available with regen when I bought the motor think I am going tory a different controller anyway I have a new controller with small display and half twist throttle I am going to try, I am going to use a torque arm made by John Bry, it was the only one I could use on my front wheel build and it is made the way I was going to make one myself( do not want to lose the front wheel)

 

[AHicks]

Absolutely LOVE Rube Goldberg imaginations.....

Where there is a will, there is a way....

 

[harryS]

Good old Rube, pretty cool guy, but I doubt one of his widgets is fast enough to disconnect the phase wire from the controller to short circuit it without inadvertantly shortcircuiting the transistors in the controller trying to power those phase wires.

KT controllers are supposed to work well with regen. They have a connector to anable it when the brakes are activated. Spend the 120 bucks for one of them with a new display.

 

[AHicks]

Good old Rube, pretty cool guy, but I doubt one of his widgets is fast enough to disconnect the phase wire from the controller to short circuit it without inadvertantly shortcircuiting the transistors in the controller trying to power those phase wires.

KT controllers are supposed to work well with regen. They have a connector to anable it when the brakes are activated. Spend the 120 bucks for one of them with a new display.

Early on/a few years back, prior to realizing how much they didn't work for me, I ran a couple of Direct drive hubs, powered with 35a KT controllers, and ridden in an area with a lot of hills. I got pretty familiar with regen and what to expect. They do work good!

The only issue I've heard of is using regen on a fully charged battery.

 

[kevinmccune]

Good old Rube, pretty cool guy, but I doubt one of his widgets is fast enough to disconnect the phase wire from the controller to short circuit it without inadvertantly shortcircuiting the transistors in the controller trying to power those phase wires.

KT controllers are supposed to work well with regen. They have a connector to anable it when the brakes are activated. Spend the 120 bucks for one of them with a new display.

been contemplating it, probably I am about to the limit on what I spend for this build.

 

[tomjasz]

I just saw an MXUS kit, not sure what the controller is branded but the voltage and amps are completely adjustable from the display. Finally, makers are listening to the DIY and LBS kit market! Around $600USD.

 

[kevinmccune]

I just saw an MXUS kit, not sure what the controller is branded but the voltage and amps are completely adjustable from the display. Finally, makers are listening to the DIY and LBS kit market! Around $600USD.

Going to check it out.