Electric Bike Stopped Working........ Help!!!!

chris301up

Pedelecer
Sep 22, 2009
244
15
I have had an electric mountain bike for a couple of years now and it has never let me down until the other evening.

When I came to use it, after fully recharging, I switched on the key, the LED lights on the indicator flickered and that was it....no power whatsoever! I checked the battery yesterday with a voltmeter and the output indicated about 40/42 volts, so it appears the battery is not at fault?

I have visually checked the wiring and there are no obvious faults or short circuits so can only assume at this stage that the fault may be the controller box? Has anyone had a similar problem and may know how, and where to begin to sort out this problem?

I have now removed the battery to help reduce the overall weight but it is still very difficult to pedal without this.

I do not know the manufacturer of the bike as this was purchased through a well known auction site, and there are no identification marks on it. I believe it was made in China and is very similar to a Whisper. The original battery was situated down behind the saddle upright stem, but because I couldn't get an original replacement I fitted what I understand to be an Alien battery on the rear rack.

Any further help or advice would be greatly appreciated!!
 

flecc

Member
Oct 25, 2006
53,195
30,602
Do you have a battery level meter on the handlebars? If so, are the LEDs lit, and if so, when you twist the throttle, do they go out?
 

chris301up

Pedelecer
Sep 22, 2009
244
15
Yes I do have a battery level meter on the handlebars which comprises of 5 or 6 small LED's. Initially they flickered, but now I don't have any lights whatsoever and nothing when I operate the throttle?

I have just removed the cover from the controller unit, but have left it wired for the time being until I know more.
 

banbury frank

Banned
Jan 13, 2011
1,565
5
Hi It sounds like the battery connector is it bent or burnt or could be a fuse in the battery

it may read 42 volts is that on the output to the controller

Frank
 

steveindenmark

Esteemed Pedelecer
Apr 10, 2011
406
2
Can you post a photo of your bike and the controller?

It may help if we can identify what model it is.

Steve
 

chris301up

Pedelecer
Sep 22, 2009
244
15
Hi. I have just checked the fuse and no problem. The voltage from the battery is both at the output socket and at the wiring within the controller unit.
 

chris301up

Pedelecer
Sep 22, 2009
244
15
Hi. I am unable to supply a photo but have the details from the controller unit as follows:

Intelligent Motor Controller
Voltage: 36 V
Embedded Voltage: 31.5 V
Model: YK79B 1.1 (Not sure if this is 7 as label is damaged)
Angle: 120
Power: 250 W
Brake Level: Low
Production Date: 2008-8
 

JuicyBike

Trade Member
Jan 26, 2009
1,671
527
Derbyshire
You may like to check if you have a second fuse that protects the BMS - a smaller fuse that may have worked loose... Some pictures would certainly help if you can get hold of a camera.
 

Scottyf

Esteemed Pedelecer
Feb 2, 2011
1,403
-1
If the LED's filkered and the battery reads 42v then there's a good chance there is a connection issue.

There isn't much to fail in controllers and electric circuits that are run at the standard required wattage.
The chances are there is something a drift in the connectors. Whether this be a throttle connector, an on switch etc...

As your bike has a pretty rusty chain I can only assume you ride in all weathers. This means the connectors if not fully waterproof will be rusting over time.

You'll probably need a multimeter to test the various connectors to find your problem.
 

banbury frank

Banned
Jan 13, 2011
1,565
5
Hi Connect you meter on the heavy red and black on the controller see if you have 42 volts if so try the motor if the voltage drops then it is ether battery or connectors

Frank
 

chris301up

Pedelecer
Sep 22, 2009
244
15
Hi. I don't normally ride out in bad weather as I tend to be a 'Fair Weather Rider' only. The chain is actually gold in colour by manufacture and I use copper lubricant which tends to give the impression of rust! But that's a minor issue for the moment.

Thanks for your advice. I am going to try to borrow a multimeter later today and go through the various connections once again - but I won't hold my breath? Maybe I will be lucky!
 

shemozzle999

Esteemed Pedelecer
Sep 28, 2009
2,826
686
Thanks for the handlebar pics.
While you are waiting for the multimeter, could you trace are the cables going back to the controller from the throttle, display, brake lever switches and pedelec sensor and post a list of the number of wires, wire colours and a description of the connector they are terminated into.
 

chris301up

Pedelecer
Sep 22, 2009
244
15
Right. We have checked out the controller with a multimeter and there is 40/42 volts at the battery output and at the controller. There is no power whatsoever from any of the other outputs from the controller.
I have now removed the controller unit which smells very slightly of burning, but that could just be the natural smell from usage?

The wires (as far as I can determine) are as follows:

1 x Orange (Positive from battery)
1 x Black (Negative in from battery)
2 x Grey (Not connected to anything)
1 x Thick Green (To motor)
1 x Thick Blue (To motor)
1 x Thick Yellow (To motor)

The following I am not sure where they go as I cannot trace them:

5 pin connector with Red-Black-Yellow-Blue-Green
3 pin connector with Red-Black-Red & Green
3 pin connector with Red-Black-Red & Blue
1 x Orange wire
1 x Black wire

I am reasonably sure this is where the fault may lie so does anyone know where I can obtain a replacement?
 

chris301up

Pedelecer
Sep 22, 2009
244
15
Thanks Frank. Have just checked it out on Ebay and it looks like the one? I think I would have to sort out a re-wire though?