Conversion finished!

That is quite a battleship! Any more infos about it?

So how will you go about making the bike street legal? Here in Germany that would be quite an expensive nightmare with the TüV, and you even welded a critical part of the frame, i.e. the rear swing arm hinges! As much as I like your approach and build, as much I hope that in Sweden the technicalities aren't as complex and expenisve as they are here in Tyskland...

Oh boy, this could get real messy now. I remember the look of those welds on your new swing arm hinges...

Congratulations on successful completion of Step 1! You must have had a good-natured approver, I think I would have given you a harder time :-) What will the next step comprise? Electrical, EMC-type testing?

The next step is actually more simple and they only check lights, brakes etc.

Ah, ok, so the normal roadworthyness stuff. That should be a piece of cake with proper vehicle preparation :-.)

Congrats! Are you using a Sevcon controller in your build? They are known for such strange behavior in combiantion with Chinese hub motors.

The simplest reason I could think of is that battery voltage sags so much at full acceleration that the controller shuts down...

If the problem is voltage sag, then why not try dropping the max current allowed through the controller quite a bit? If that solves it, you can then up the current again in increments until you hit the sag, and leave it set just below that point.

When the ZEV was low on juice it behaved just that way, cutting the current completely when the throttle was opened a lot. I've never encountered that with a lithium pack on my bicycles, but then all of my bicycle motors draw no more than maybe 600 watts, max. I can *see* the voltage sag start on the rare occasions when the packs get low, though, through the primitive voltage indicator lights. I assume that you have some sort of instrumentation that shows voltage; can't you look at what's happening with that when the controller cuts out? If not, a voltmeter of some sort might be in order.

Let's see: Phil Carlson of Canberra comes to mind with his sevcon-powered PDT erider Lightning Bolt, who reported on these odd situations when trying to accelerate while turning into another road, especially when the road was a little steeper. I have heard from the first Sevcon-powered erider Pumas that they suffered from this random cutout phenomenon, which appeard to be unsolvable, so erider changed to other vector controllers and thus sent out an email that you surely also got that they have quite a number Sevcon controllers for sale for little money, even with a pic of a heap of Sevcon controllers.

I just had to rework the erider stator on my second motor, as it was so eccentric that a little bearing play already led to increasingly massive rotor magent rubbing on the stator. My full report is on the German-language Elektroller-Forum, but with a LOT of photos! And you can see the photos WITHOUT having register there, unlike the DIY electric forum :-(
http://www.elektroroller-forum.de/E-Roller-Forum/viewtopic.php?f=19&t=3785
The stator was some 0.3mm excentric, which I was able to take off on the lathe of a friend, by temporarily turning the stator into a rotor. And the brake-disk-side drive shaft diameter was another 0.3mm too small, so I had to bring it to the proper 15mm diameter with 4 rows of punch marks. A test ride comparing max acceleration data (battery current/voltage & speed over time) after the rework with original state will follow once my Swiss-chinese ride is back from a proper reworking of the GoldenMotor conversion that was done mechanically correctly. Until then my Thunder with the third motor will be my daily ride, too much risk in changing the motor out :-)

Did your TC die with a pop, smell, etc., or completely unspectacularly? And had you used that charger in a previous project already, i.e. was it already used before?

So it was a new charger, never used in another project? Something like dead on arrival, apart from a handful of charges?