[protoserge]

You will want to design it for a 30" door opening. While 36" is the standard for exterior doors, many interior doors are 30" or 32". That one time you need to go through a narrow door, you'll be thankful.

I agree with the points about not having an unnecessarily complex charging system on the cart. Just get some battery chargers and extension cords. You should never be without wall power. Safety inspectors may tell you to disconnect a charging system for a deep cycle battery in the pits.

I also agree with others' statements regarding separate carts. Don't try to have a single cart for everything; instead, separate it out into mechanical, electrical, and battery charging. These don't need to be massive carts. Electrical may only need an 18"x18" table top and chest of drawers.

A good project for sure!