I don’t know how simple or not simple this would be to implement, I’m guessing not simple, but…
I’d think that the game would be improved by making a tool-mod for things like, well, any tool that takes batteries. If the tool is located on any square that has vehicular power - say, a vehicle, but also just a shopping trolley onto which you’ve welded a storage battery - then the tool draws from the vehicular power instead.
Yes, this would effectively made vehicular welders and some of the vehicular tools obsolete, but I have a couple of alternative proposals that can address that:
1] Just let them go obsolete, and replace the ones that are not combo-tools (like the FOODCO Kitchen Buddy, RV Kitchen Unit and Onboard Chemistry Lab,) with a generic vehicular tool storage tile that’s not meaningfully different from the existing ones, just looks similar so it’s easy to tell apart from, say, random storage areas.
2] Make the tools which compromise the vehicular tools specifically prohibited from being tapped into vehicular power in this way.
3] Make the vehicular versions superior in some small but measurable manner, such that players would still be incentivized to go to the time and trouble of making them.
4] Rig it so that instead of “any square with vehicular power,” the cord-modded tools draw specifically only if they’re placed in those specific types of tiles - a corded power drill would need to be placed in a square containing a vehicle-mounted welder to be properly used.