More than once I have almost been stranded somewhere because I wasn't paying any attention to the SOC indicator. Probably some of you have had similar experiences.
Then it occured to me that maybe one of those small 1000 watt portable generators could be carried in the back of the Zenn and used as a 110 volt emergency power source for the charger when the batteries run out of juice and no outlets are available. All one need do is lift the generator out of the car (this class of generator is not heavy), move it a few feet away, start it up, plug in the 110 volt extension cord to the generator, and plug the other end into the onboard charger socket.
After 15 or 20 minutes of charging, I would be on the road again (Thanks, Willy).
The 1000 watt generators I have seen measure about 12 inches by 12 inches by 12 inches and weigh around 45 pounds. They are capable of generating 10 amps of 60 Hz, single phase, 110 volt power - and usually have 2-cycle motors that require oil to be mixed with the gasoline. Such generators range in price from $100 to $200.
What are your thoughts, pro and con?