Power supply options in the car when traveling?

Since I want to travel and sleep in my car for several months, in which I will install a mattress, I'm currently finding out about the options I have for power supply.

For example, I can charge my mobile phone while driving. This is also the most important as I will need it to navigate or to research different destinations or camping pitches. But since this is only loaded while driving, I still need alternatives how I can load it otherwise…

Occasionally, I may have to charge my laptop. Who has recommendations what is inexpensive and is specifically intended for my use?

I've heard of variants like gas and solar. However, it is difficult for me to find out what is best for me. A power bank would be too little for my cell phone. Then I would need a larger "battery" on which I can charge the cell phone more often. Any suggestions?

So that you can charge your notebook on the go, take a small inverter with you. Example: https://www.rakuten.de/produkt/msw-spannungswandler-12v-300-600-watt-inverter-wechselrichter-230v-ladegeraet-kfz-2764762180?sclid=p_shopzilla_DE_2764762180_mid142780_mrchbasic_catidauto_prc_35.00_type_ean&cid=affiliate

The cell phone does not draw a lot of electricity, which is why you can easily charge it from the car battery while standing (e.g. At night). You may have to put the cigarette lighter or another can (via a fuse) on Permanent Plus (e.g. Terminal 30 or B +)

I would only make the detour via 230V if there are other devices that need this voltage. With 300W you are very limited.

Something like that is enough to charge a laptop: https://t1p.de/iyoj

In fact, that's even better, it wasn't clear to me that there are such affordable, customizable step-up converters in the power range.

The safest variant in terms of reliability would be a gas generator.
But that is financially too time-consuming and exaggerated for a car.

I would also recommend the idea already mentioned with a second battery, which you can use separately.
So you have a power source for the rest hours with which you can operate laptop and light, during the next trip the battery will be charged again.

There are such power supplies for the laptop: https://t1p.de/iyoj

Or you play it safe and take a small power generator with you.
It makes a bit of noise and therefore can't be used everywhere,
but you are also independent and on the safe side.
https://www.testberichte.de/p/zipper-maschinen-tests/zi-ste-950-testbericht.html

If it's not a bus or van, your endeavor is pretty limited. In a normal car you are completely finished after a few nights. If the whole thing should go on for months, get a motorhome. There you have a reasonable bed, a heater, (you don't want to sleep in the car in winter) you usually have a shower (it's worth gold) and your own toilet. (Even more important than the shower 😅) you can also stand in it sensibly. And you have a way to connect electricity from outside

Drive my little Fiat Punto by installing a bed. Have done the whole number of times and I really enjoy it