Every off-the-shelf complete E-bike that I have seen so far ( in Amsterdam) , has a proprietary electrical system that only the authorized dealer can get parts for.  

The Dutch brands Sparta and Batavus require a confidential computer code to be entered into the bike's charge controller by an authorized retailer, to even replace a battery.

 (Customers are typically not informed of this at point of purchase.. they find out a couple of years later that a battery replacement will cost them €500 )

It gets worse with conversion kits.  Each kit  has a proprietary motor controller, battery and charge control circuit, and each of these components are incompatible with those of other manufacturers.  I have seen a few quality control problems on cheaper kits, that 

( I've read that the Stoke Monkey kit has parts that can be bought off the shelf at an electrical supplier, but I have not seen one in person )

My partner is an electrical engineer who has built up ( and attempted to repair ) hub motors and several electrification kits on his own bikes, 

It appears that mixing and matching a working system from parts of E-bike kits, from different manufacturers, simply can't be done, at least in our experience.

I agree that E-bike riders are cyclists too … but procuring parts for an e-bike is a very different experience than with a mechanical bike, and if you don't have parts from the original manufacturer, you might be avoiding some grief to have a policy against working on them in your shop.

Does anyone out there have any experience with working on E-bikes they would like to share?

Wendy Monroe