MPIII - 81 miles then BOOM!...

[Bedmountain]

Hi all,

I'm just back from a rather unpleasant trip out on my new MP3...

6 miles into the ride the motor cutout (I've had problems with LVC under heavy load previously). This time it cutout when under a light load - around 150watts. It cutoff again a few minutes later.

I turned around but the cutoff started to occur more and more frequently. I was getting about 30 seconds of power then cutoff again. Switching the battery off did not turn my CA screen off which seemed a bit weird. The CA was showing a slow drop in volts when the battery was switched off.

I thought I was going to be able to limp home but after a mile of on off motor it cut out completely and the back wheel suddenly became difficult to turn so that was the end of that. It was a long walk home...

Now I'm back and there is a fair bit of resistance from the motor when I turn the rear wheel by hand.
I suspect something is now broken in the motor?

I'm gutted  . I've only travelled 81 miles on it but I'm addicted already!

Can anyone offer any opinion on what could have happened or any advice as to how I can start to troubleshoot this?

Thanks
Ben

[skylinenitro]

Disconnect all your wires and see if the wheel turns better.  If not, you might want to remove your controller and inspect it for burnt stuff. 

But your symptoms sounds like a bad battery, or BMS...

Also check all your wires for nicks or cuts or melts.  Let us know what you find.

[Bedmountain]

Thanks skyline.

I just took the controller out and it does look burnt (see pic).

If I remove the blue wire from the controller the motor turns freely again.

I'm waiting on a response from GM Canada regarding next steps...

Have also noticed that the controller cover has been badly scored (see pic) by the countersunk screws used to hold the outer cover on (They are too long!). There is a very small nick in the main wire coming out of the controller at this point so that may be responsible?

[e-lmer]

Gregor:

The forum is here to help people with problems, so it is no
wonder you only hear about troubles.

Ben;

Your battery does not seem to be working properly.

I am assuming that with 80+Miles you are out of warranty.

If you carefully remove the cover and slide the battery
pack out, you should be able to measure the individual
cell levels.   

I think you are going to find that one or more of the cells
is dead.  I also think replacement cells are available.
CAUTION: These babys will start fires if you short them.
If you are not comfortable with electricity then seek help.

To All:

If you drag the voltage of a Lithium cell below a certain level
then that cell is ruined.

That is why the BMS is so important, and why it is essential
that you turn the power off when not in use.  I actually
unplug the power from the battery when I am not going to
use it for a while.

[Bedmountain]

and a damaged battery could blow the controller?

[Bikemad]

Have also noticed that the controller cover has been badly scored (see pic) by the countersunk screws used to hold the outer cover on (They are too long!). There is a very small nick in the main wire coming out of the controller at this point so that may be responsible?

Ben, it's the bolts holding your brake disc in place that are too long, not the countersunk screws that hold the cover on.

If the ends of the bolts have cut into the individual wires they could easily have shorted two or more of them together causing the controller to fail.

As the MPIII does not come with a disk already fitted, the disc retaining bolts (that are clearly too long) must have been fitted by you during the conversion. It's a shame you didn't notice that the wheel was binding on the bolts making it difficult to turn the wheel before you rode the bike for 81 miles.

Alan
 

[Bedmountain]

  - It appears I'm an idiot!....

I really couldn't tell that the wheel was particularly difficult to turn although it's my first conversion so I didn't know if I should expect a bit of resistance (it was surprisingly easy to turn considering just how much those bolts have scored into the controller cover!)

On closer inspection of the controller wire it seems unlikely that the wire has shorted at that point.

Need a new controller now 

and a new battery as my 10amp continuous discharge battery isn't up to the job

Not going too well all in all....

[Bedmountain]

In my (albeit weak) defence...

The disc retaining bolts are 10mm long which seems to be a very standard length (I can't find any shorter)

I'm not sure how I managed to tighten the bolts up in the first place as they would surely have bottomed out against the controller cover when I fitted the brake disc?

[Bikemad]

Cheer up Ben, hopefully it won't be too long before you get your next fix for your recently diagnosed eBike addiction.

Unfortunately, I could not find anything available on prescription to help with the withdrawal symptoms that you are currently experiencing, so you'll have to just try not to think about it too much, as I'm sure there will be countless eBike miles for you to thoroughly enjoy when your problems are sorted.

Alan
 

[GM Canada]

Hi Ben,

I have just returned from vacation. I am behind on everything. I seem to recall an email from you. I am not sure if I replied. If you need help click the warranty link on the bottom of this post.

Gary

[Bedmountain]

Thanks Gary

I have a ticket open in which I have placed as much detail as I can.

Regards
Ben