I have and still do use Ryobi 18 volt One products while on the road. They have up to a 9 AH battery and I use a couple of these with several 4 AH batteries as well. I charge them using an in vehicle charger while driving or parked using solar. I started out using their tools to build a camper and since I had the batteries decided I didn't want to deal with a lot of interior wiring or fixtures. It was much easier to hang a couple wire baskets which happened to be just the right size to hold the battery and desk lamp which the handle wedged against the ceiling to keep it there. When I started using the heater I needed a fan Ryobi had a robust dual power one on sale. The next summer while working a in a hot building I got an Artic brand misting fan that is totally self contained and uses any 5 gallon bucket for a base and water reservoir at Home Depot and surprise the Ryobi batteries fit. I also picked up an 1/2" impact and a tire inflator for emergencies. I don't like using the vehicle battery for anything but starting the vehicle. I have a wet dry vacuum and am also thinking about the new 150 watt power station they offer. Avoid the temptation to buy the off brand batteries, the HP series have lasted 4 years now with no complaints and as they are lithium were the cheap way at the time to try the new tech as lithiums in 12 volt were almost twice as much as they are now. The new brushless tools look to be better also but I haven't tried them. I get up to 8 hours use out of the 9 AH with the fan on high. Crazy how many specialized tools they come out with but the batteries will fit any of the One tools. Buy with a Home Depot card and you get a bring it back type warranty at any store, but be sure to check that to make sure. There are a lot better tools out there but none that put the electronics in the battery so it fits any of the tools which makes the batteries the big cost.