If you’re interested in welding plastic, find your local Matco dealer. Matco makes a welding kit with instructions on determining the plastic that you’re trying to weld as well as filler rods for various plastics.
I found the product page here.
I should note that while a plastic battery box stands up to the spills and fumes from lead-acid batteries much better you’ll still need to have a frame of some sort to contain the batteries.
Electric car hubs. I found these for my project.
I have an 1993 Mazda MX-3 I was thinking of converting to hub motors found your site while trying to research batteries. Love the info I still need a battery site to get educated a bit more. Down side of this place is they want larger orders not set up for Home builder.
Just wandering, how strong is one of this plastic battery box?