Electric Chopper project "Panther"



Hi all.

I WAS building a "Happy Time" Schwinn OCC (Lookalike) chopper which I intended to Register and insure as a moped here in BC Canada but I have been told by those who know that I would be better off to start from a motorcycle frame from a legal standpoint.

So instead of a "Street legal" build I am starting a decidedly illegally overpowered "pedal assist" chopper. In BC we are limited to 800 Watts maximum.

I think my motor is 1600 Watts:devilish:

It came from an Invacare Panther MX-4. A very BIG 4 wheeled mobility scooter. I got the whole scooter from a dealer who was tired of trying to repair the throttle unit (not the controller) for $100

It took days to pull it all apart and extract the electrical harness, lights, motor and controller.

"Panther" seems like an appropriate name for the project. Both because the scooter was called Panther and because I should end up with a powerful yet quiet killer.;)

Pix to follow.



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Sounds like a great project. I hope you will detail the whole build for us. Some day we may all be riding electric.


Active Member
Dec 15, 2006
this is gonna be an interesting project...thanks for including us in the fun !!!:D:D:D

Large Filipino

That's pretty cool. Now I know power scooters aren't exactly fast but they pull pretty darn well. I'd like to see where this all goes. With the right gearing you may get better range than any power scooter can get,and power scooters are designed to run all day.
You may have found the answer to electric range issues.


scooters aren't exactly fast but they pull pretty darn well. . With the right gearing you may get better range than any power scooter can get said:
I doubt it. Scooters get great range because they are slow.They are slow because they are geared really low. One PM DC motor is pretty well the same as any other...You could probably go just as far with a bike as you do with a scooter with the advantage that you get there faster! (And therefore run out of juice faster.)

On the subject of speed,duration,acceleration et. Does anybody happen to know the wattage of this motor? I found the current replacement speed controllers manufacturers website and the "Solo" series of controllers from Penny and Giles in England range from 60 Amps on up. There is what looks like a relay on the circuit board that says "12 Volts 70 Amp" but this does not mean the motor draws that much. Besides this is definitely a 24V ESC. Weird...

The gent who sold it to me said it was either 1.5 or 2 Horsepower (Not just somewhere in that range but either one or the other)which would put the motor at either 1118.55W. or 1491.4W

But the ESC has a component which claims only 840W.:cry:

Was I lied to? It's an awfully big motor and he seemed to know for sure.

Can anybody help?


P.S. It's a Pihsiang Machinery Mfg. Co. Ltd. M3-9mnf-2a (order code)
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I meant to begin a build thread in General Discussion it it ok if this stays here? Or should I begin again in GD?

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Battieries on Saturday etc.

Batteries are coming on Saturday. 2X 12Volt 37!! AH Deep cycle SLA.

This is aprox. what the Panther used (40AH) So I should get good range.

I have a problem however. The throttle unit was the only piece I didn't get with the scooter (broken). I know that it must be a potentiometer but what resistance and current handling?

Also anybody who knows about scooters what would you expect my full throttle rpm to be? Can I bypass the power controller at full speed to just dump 24Volts directly to the motor? Can I overvolt a bit?