need more, including Dell needing 19 volts

For almost all laptops you can buy a charger that plugs in to a 12 volt "cigarette" lighter outlet. They are neither as wasteful of energy nor as noisy as some inverters.

It has to match the computer, both for the physical plug and for some electrical trickery, so buy form a compouter shop, on line if you wish, but specify the computer it is for.
Dell makes a neat one for up to about 100 watts that can plug into 12 v or 110, or 220 volts as you wish
These are meant for cars, and since car outlets are almost all limited to 125 watts, the chargers on the market are sized correspondingly.
I have a Dell mobile workstation laptop that wants 150 watts, and ther is no 12 volt charger on the market for it. The stupid machine refuses to charge slowly on a smaller charger.

Bats today should have lots of cigarette lighter type outlets (not actual lighter sockets, but the marine ones sold by the chandlers) We started with about 6, and now have 17. iThings etc plug into them with the tiny USB adapters.