Van Dwelling/Power Systems
Consult a marine store for advice on power systems. In general many problems applying to van dwelling are equally applicable to boating and vice versa.
Power will probably be hard to come by without some money. That said, you can try going to some place where old batteries are discharged. Supposedly, if a commercial grade computer UPS dies, sometimes it will be only be one of the batteries that have died, and the others are salvageable. Many products proport to be able to restore batteries killed through misuse, and not the normal abrupt battery death.
Typical Power Needs
Depending on your needs you may or may not even need power. If you are in survival mode and without cash, you may not even need any power. My goal is to be able to study and learn and contribute back to the internet via programming. For this I need a permanent and cheap way of living. Hence my van is essentially a computing pod and therefore has moderate power needs.
Consult the [Deep cycle battery FAQ]
Purchase a deep cycle battery or (untested) dual cycle. A friend recommends purchasing 4 batteries, wiring them in parallel, and then setting up a diode from the alternator or generator to charge them whenever the engine is on.
- Park at an RV station once a week to recharge.
Generators are the most practical but they require gas. There are new efficient and quiet models which probably will help with discretion.
This is the most constraining in terms of location but can generate lots of sustainable power. Consult the standard references.
Solar power generation is expensive but recalcitrant.
The panels were more fragile then I expected.
Putting solar panels on top of the van blows cover and makes you are target of theft and vandalism. I put them in the passenger compartment right behind the seats, and there is an unquantified charge on the charge controller. The biggest problem is that they are detectable at point blank. If you have a cargo van with racks you can try hiding them in a ladder or something, and/or placing a tarp over them that you can control showing them. Another technique is to blend and mask them on the roof, maybe using wire or something that obscures visibility, to the detriment of efficiency.
If you are out camping then you can simply let them outside provided they don't exceed the scope of your security system.
Setting up a magnetic resistance bicycle to generate power could work but would not generate usable amounts of power for larger applications.