Most the chargers have a HUGE plastic container for the damned electronics to communicate with the car. Now the ones that show you KW/hr, power used, elapsed and all the bells and whistles I can see but if all you want is JUST a simple interface to turn the damned power on to charge your car, that actual part really is just a small chip /circuit board really. You could really about put one inline on the cord, and it'd fit easily in the head of the cord w/o the HUGE box inbetween the plug and cable.
I am in the process of making a super compact cable to try an experiment. The J plug side, I am going to just pot the pins in some acrylic, at the proper spacing to fit into the plug side, it'll be a small flat puck with the pins sitting out eseentially. (since the Ribelle will never take more than 15 amps, I don't need HUGE honking cables coming out of it, 12 ga is perfect for power, 16 for signal). You can use heat shrink to make an insulating jacket for cables, so I will run them flat, and shrink them like a flat cable so they fit very easily under the seat of the bike and all it will have is a small female plug head right there.
Now all I need is 12 GA extension cord wire to bring up to 15 amps to the bike, (yes technically I could get away with 14 ga but I want the little safety overhead), with a few pigtail heads to form fit the plug and I can charge anywhere, without having to lift the seat.
The seat lift is concerning to me because, what if your charging at a station somewhere with the seat up and it starts raining into your stuff? I think that would be a BAD day, this way, you can charge in the drizzle / light rain and your bikes sensitive power block is still protected.
TBH I don't understand why ALL manu's just don't put the little chip ON their bike and it's all built in. For L1 or L2 charging, which is mains charging, you just plug a damned cord into the bike and the rest is handled BY the bike, like it is now. Once the warranty is gone off my bike I plan on doing just this. It'll easily fit in the area under the seat where the charger is tucked in at.
Aaron