I had a Twizy Technic 80 for 2 years and was mostly happy with it. Used it summer and winter here in Sweden, which was quite an experience. My biggest qualm was the limited distance covered by the battery, roughly 80 km, at best, usually no more than 70. Since my office is 35 km from home, I often found myself forced to stop by an IKEA or McDonalds to charge for an hour on my way home, since there are no outdoor power outlets available where I work.
My idea is to install an extra battery pack to be securely fasten on the rear of the vehicle, using something like this rack. It should carry about 2-3 kWh of charge and would let me connect the Twizy cable to it when I arrive at work. That way I could add an additional 20-30 km to my daily commuting distance. Once home I would simply connect both the Twizy and the battery pack to my outlets and charge both.
I’m not trained or educated in electrical engineering so I don’t know what type of battery packs would be suitable for this, but it would need to be weather-proof, have a standard 220V outlet it and weigh no more than 50 kg/140 lbs. Basically a Tesla Powerwall, but smaller.
Any ideas on how to make this work?