Car battery mod?

Is there such a thing as a ‘car battery mod’ (like the medium battery mod, etc.)

It would be really, really, useful right now. I have electronics 3 and I don’t know any way of grinding it up with the equipment I have. I also have a makeshift welder that would be super useful if it had a compatible battery.

This ?

Aha, that’s the one. Pity I can’t actually make it because I have no charged batteries for my soldering iron (and no solder).