Vaeagleav, therein lies the problems with the limitations of an electric vehicle and is likely the reason that people have the perception that they do of electric vehicles. To extend the run time, they have to limit the amount of current that the motor can draw at WOT during acceleration.
A decade or so ago, the limitation of charging a battery for an EV was the time it took to charge the battery. I don't think that applies so much any longer on the battery side. What I mean is that lithium based cells can now be charged at a rate of 1C per hour. "C" being the capacity of the battery. I've seen cells take can take up to 3C. Essentially, what that means is that the battery will charge in an hour or less, IF you can provide the current from the charging system.
I really don't know what size battery you'd need to push an electric system in an Avy EV. I would imagine that ideally, it would be based on a 110, or even better, a 220 volt system to help keep current draw down. I really wish I was stronger in the math department.
Ideally, I'd like an Avy with the system restricted to match the power of an 8.0l. As for the batteries, I'd imagine that someone creative could come up with a place to put them in a place that wouldn't compromise the utility of an Avy. Since you're gonna be getting rid of the big bulky engine and transmission, I think there would be room, although it's gonna require some out of the box thinking.
As for needing a mechanic, I don't know. I'd guess that the two most common problems are going to be either a dead battery or a fried controller. There really isn't much to break.