Get a 12V inverter and a normal 120V AC fast charging adapter. It seems silly to turn DC into AC then back into DC, but it’s totally worth it when you need a lot of charge fast.
There are 12V inverters that plug into cigarette lighter ports. Some use a wire, and some just stick out of the port.
You can also get “fast” charging USB ports that stick in your cigarette lighter, but they are never as good as a proper charging adapter. Maybe nowadays you can find a real fast charging one now that USB-C fast charging standards are a thing. I haven’t shopped for one in a long time.
I just gotta say… The ability to edit titles on Lemmy is so smart. Especially for cases like yours. Thanks for adding “Solved”!