My Motor Runs But There is No Drive!!! HELPPPPPPP!!!!!!

ace_bridger

Finding my (electric) wheels
Jun 28, 2011
20
0
I've bought a secondhand Powabyke Mk1 wheel, controller and throttle and have just fitted it to my bike.

I've plugged everything in and when I switch it on the motor runs, despite the throttle being in the closed position, and I can hear it running nicely but there is no drive to the wheel...very puzzling.

Has anyone got ideas before I strip down the hub motor and inspect it?
 

flecc

Member
Oct 25, 2006
53,152
30,567
Are you sure the motor is really running? If a hub motor and controller are incorrectly wired, it can sometimes result in a loud hum and vibration that appears as though the motor is running, those reactions just coming from the coil windings carrying current but with no drive. So recheck the wiring first.

If it is actually running it will be the drive cog or toothed rack internally that's failed.
 

HarryB

Esteemed Pedelecer
Jan 22, 2007
1,317
3
London
Are you sure it is not running backwards ie the wiring has been confused? You woul hear it running but the freewheel would prevent the wheel moving.
 

ace_bridger

Finding my (electric) wheels
Jun 28, 2011
20
0
Sorted! I took a punt and swapped the connections at the motor, I figured it couldn't do any harm (!), and away it went (after a few sparks and a little black smoke!!) !!

Another problem is that as soon as I turned the controller on the motor runs. I've got it connected via an additional switch at present but it would appear that the throttle is not doing its job. i disconnected it and that made no difference.

Good news is though that I've just taken it around the block and it works like a dream. A working throttle would add a huge amount but even with my on/off switch it's great!! I need to do a dry run to work and back this weekend before attempting it for real!

I've made up a 36 V 7.5 Ah SLA pack and have enough batteries to make a 15 Ah pack too so we'll see what ranges I get from them.

Thanks for the assistance and advice and if you have any idea what might be wrong with the throttle I'd be pleased to have your opinions.

Cheers,

Adam
 

flecc

Member
Oct 25, 2006
53,152
30,567
Harry's answer was obviously the right one Adam, so I wonder if the controller connections now also need to be reversed?
 

flecc

Member
Oct 25, 2006
53,152
30,567
It is a brush motor.

Frank's suggestion seems likely as there's a post in another thread about just this. It's on this link.
.
 
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ace_bridger

Finding my (electric) wheels
Jun 28, 2011
20
0
This is all good info thanks guys!! I think you're right, I've blown the board, and by the sounds of it the MOSFET.

So, assuming I've been a dullard and connected the battery with reverse polarity I wonder how I did it. I wired a female kettle lead with battery +ve to the live terminal and the battery -ve to the neutral terminal and plugged it into the kettle lead which comes from the controller. Then found that the motor ran backwards so swapped the motor connections over and it ran forwards.

I just tried swapping over the battery connections AND the motor connections (so that the motor connections are back to normal) and there was no life at all when I powered it up, the motor didn't run. I assume that this is just because the controller is blown. I swapped everything back over and everything is back to normal (motor running forwards flat out).

I don't want to spent money on a new controller only to blow it again!!

What we do in our sheds eh?

Good news is that the bike performed brilliantly on the full test run today and took me to work and back (with Mrs Me following in the car!!). On a 7.5 Ah pack I got 12 miles and there was still juice in it.

Very pleased. Just need to get it running with the throttle and I'll be super happy!!
 

ace_bridger

Finding my (electric) wheels
Jun 28, 2011
20
0
Yep, I've just checked the pictures Frank sent me and have noticed that the battery is connected up the other way round...woops. Yes, I know, I should have looked before I lept but I got excited and followed the plug connections...silly me.

I'll buy a new controller and check before blowing that one up!!

Thanks guys!!