Lots of good suggestions, but here’s two I didn’t see mentioned.
12-volt tire inflator. Tremendously useful for every time air is needed but isn’t close by. Trailer tires, ATV tires, etc, etc. Saves a lot of driving around to find air.
Also great in an emergency to air up a punctured tire just to move to a safer place to change the tire. I also carry a tire plug kit, which has come in handy more than once. Put a hole in a tire on a Canada trip and yeah, I’ve got a spare but there is no spare to the spare so I don’t want to be without a backup. Very reassuring to be able to patch your own tire if the need comes up.
Also, I have a 12 volt inverter. Just a small one, but great for recharging anything that needs 120 volts like laptops, cordless drill batteries, etc. Also great for running small tools like a chainsaw sharpener. Really a time saver.
Grouse