Electric Scooter/Moped repair - Fuel Economy, Hypermiling, EcoModding News and Forum

WVengr · 08-10-2011, 09:58 PM

I just purchased a electric scooter for $8, but it doesn't run. it turns on but the throttle does nothing, just makes it wine. It appears to be wrecked. Picked it up because it was dirt cheap and will give me something gasoline free to use when i am on short trips that don't need my truck. It has a potentiometer hand throttle, turn signals and headlights and brake lights, and has the name sunway on it. It also came with the charger, and i do have a charge on the batteries. I know nothing about it, but would like some tips on where to start fixing it. I figure if i can tackle this I might have what it takes to start working on electric cars, so any help would be appreciated.

Ryland · 08-10-2011, 10:56 PM

I am going to assume that it has a 24v battery pack so it has two 12v batteries, right? what is there voltage after charging and while "under load", in other words what is there voltage once you turn it on and twist the throttle, my guess is that even tho you "charged the batteries" that they are dead and not taking a charge.
It's like trying to get something with a gas engine to go, first make sure there is gas in the tank.

Also, you said it makes a sound... what makes a sound, the motor, the speed controller, the horn?

WVengr · 08-10-2011, 11:41 PM

the motor makes a high pitched wine but doesn't turn, and the battery guage on the scooter says it is at half charge. (didn't want to risk charging it while i wasn't home so i unplugged it before i left) i will charge it more tomorrow to be sure. you are correct in that it has two 12v batteries.

I guess i should also check local laws to see if i can use it on the streets, if it had pedals it would be a bicycle and i would be ok, but it does not, if it was gas powered it would be a moped, and would need registered but again it isn't. I hope i don't have to get it registered because that may be a pain since i got it from a second hand shop (Goodwill) and I am sure there is no Vin or anything like that on it. I just moved to Delaware and don't know the rules here and the DMV's website is a bit vague, so i might have to just take it to them and ask.

Ryland · 08-11-2011, 10:46 PM

So when you turn it on and have the motor make that sound, the battery gauge drops to zero?
99% of the time, if the motor turns without a grinding sound or a bad wobble then the issue is not in the motor.
I'm sticking with the batteries being shot, at least one of them is shot.

WVengr · 08-15-2011, 11:32 AM

Ok so i did some more testing, and it seems that the batteries are indeed shot, and so is the throttle potentiometer, but i have run into another problem. apparently this thing is not legal to ride on the streets here. It would be if it also had pedals like a bicycle, but it isn't a bicycle because of no pedals, and it doesn't meet the states requirements to be a moped from a safety standpoint. Looks like for it to be legal i need to have pedals, so I may be Building a Human/Electric Hybrid Bicycle with the parts now, since I can use the controller, motor, overrunning clutch and everything from it to build it.

DonR · 08-15-2011, 11:55 AM

So mount some pedals on it from a junk bike. See if they go for it. I would try this before getting new batteries & pot.

See if there is a way to mount a bicycle freewheel onto it so the pedals are actually usable for when the batteries go dead. Think of yourself as a range extending generator.

Or just use it as a battery powered mini-bike & have some fun.