I’m thinking about using only 12V power in the van.
Why? The wiring will be a lot easier. It’s safer (when a noobie like me does the wiring). It’s cheaper. No need for solar/generator.
I won’t be living in it 24/7, just weekends or so. So I will have some extra car batteries for power (which will charge when the engine is running or back at home), use 12V fans, water pumps, regular car charger for charging iPhone and MacBook, 12V LED-strips for lights, gas stove (and water heater) and diesel heater.
Is this idea even going to work? Any good ideas? What should I be worried about?
I have watched more than a hundred van builds and they are never only on 12v
I live in northern Europe and I’m afraid the solar system will be a waste of money.
Will the 12v fans provide enough air circulation?
What type of toilet would be best (most hygienic and least smelly) for weekend use? I mean it will be unused most of the days and after the weekend I just want to empty it and leave it as is. If it’s possible with any type of camper toilet?
No reason it shouldn’t work. Everything in my van is 12 volts. The only thing you should worry about is drawing down the starting battery. They make battery isolators that prevent this. It isolates the starting battery from the house battery when the engine isn’t running, so even if you run out of power for your fans, lights, device charging, etc. you’ll still be able to start the van.
Other than that, you should probably calculate how much power you use on a daily basis vs. how much charge you supply to the batteries. There’s also the issue of using an old starting battery as a house battery - they’re not built for it, and won’t last long. You’ll need some kind of deep cycle battery.
We only use 12v so I don’t see why it wouldn’t work for you. What you are describing is what I consider a normal setup for electric in a van. You probably still will need solar or a generator if you are attempting are power all of that for an entire weekend.
I installed Dometic 302320081 320 Series toilet in my van. Toilet performed excellent- height was perfect - almost equal to our residential toilet. Quite costly but worth the money - only down side was the company supplying the toilet would not even consider a discount even though almost immediately after my order was processed that day the item was advertised from them at a lower price-they blamed Amazon for offering the discount & my only option was to return the item at my expense.
