Electricity in the camper van?

I'm currently converting an Iveco Daily into a camper and am very undecided how to deal with the installation of electricity.

I didn't really want to install anything new, just to charge my devices when I drove the cigarette lighter.

Is it advisable to buy an adapter for the lighter, with which you have 4 USB ports, and to charge a laptop via another lighter apdatper, or is that too much and the laptop and the cell phone take forever to get them are full? Or do I even use it to empty the battery?

Do 5 or 12 v come out of the lighter, do the devices charge so ineffectively and the battery breaks down faster?

Another consideration would be to charge a second battery when driving, since there's already electricity in the cargo area for previously installed lamps. Can I simply attach another battery to it and then charge my devices when the car is stationary?

Or is there a foldable solar cell that is simply put outside to help and then charge the devices?

I thank you in advance for your answers.

There are different power supply options. But I would definitely advise you to use a second battery that is only responsible for the power supply in the living area. You can also pair it with the alternator so that it is charged by it when driving. The key point here would be a cut-off relay or a charge booster. You can also use this structure later, e.g. Expand by photovoltaics and / or shore power. As required.

Without a second battery, you always have to start the engine when you want to charge something.

12V comes from the lighter, but a USB adapter converts it to 5V. If you want to charge quickly, the adapter must of course support the fast charging mode of your cell phone / laptop.

To get such a car battery empty, you would have to charge your laptop 10-20 times without driving the car in between, depending on the size of the laptop battery and the charge level of the car battery. You can probably charge a cell phone 50-100 times.

Solar cells only make sense if the car is parked for a long time and you have to charge the laptop more often in that time. Of course, you would also need a battery or a power bank, which you then charge with the solar cells, because you don't want to charge your laptop only when the sun is shining. In theory, you could also charge the car battery with the solar cells, but mostly an extra power bank is used.

Incidentally, there are various videos on the subject on YouTube.