I like the plug idea but…It would have to be coupled with some kind of manual override so that you could prevent the computer from going into “forced charging” mode and recharging the battery when it gets low, and you want to do it at home. As long as you are putting in override switches then add another one to allow more electrical assist than it would normally give also. The computer could still prevent radical over/under charging.

Back to the plug...Change the electrical system to run on 120VAC or preferably 240VAC and double the battery capacity to: Allow greater range on assist, plug in to your house/household appliances with a minimal amount of converting, and during power failures you could plug your car into your main electrical panel (after disconnecting from the grid of course) and power up your house on the car’s battery and/or motor. You could have another switch “Generator” to put your car into generator mode.