After upgrading to off-grid power and power storage, this post elaborates on the available power generating tools for a small RV. The electrical calculations are comprised into a detailed schematic overview, that serves as the basis for the installation.
Alternator
The extra power from the alternator can be directed to the battery bank, to give the batteries an extra charge while driving. You likely have to install a heavier alternator.
I plan to move little once at my vacation destinations and as my research indicated a possible limited benefit, I will forego this option at this time.
Power Grid
Staying completely off-grid (boondocking or stealth camping) is the goal, but as the situation may require, a visit to a campground is an opportunity to replenish some battery power.
The battery charger is connected to the 110V external power inlet, that in turn can be connected to a 15 amp electrical outlet with a heavy extension cord.
With 420Ah in batteries and a charger rated for 15%-30% of it, the IOTA DLS-55 55 amp charger would be a perfect fit.
Generator
With a van, storage is always a major issue. In addition, the fuel is dangerous and smelly.
Personally, I never understood, why one goes through the trouble of finding that one, exclusive location, to have it disturbed by the noise of a running generator.
Solar
Panels are largely maintenance free and prices are still coming down. They are a great solution for off-grid camping, with some limitations on cloudy or rainy days.
With 420Ah in the battery bank, a balanced system ideally requires an equal amount in watts (420W) as panels.
That poses the problem of roof space on a (cargo) van. On my current Dodge, the available space is limited to 100” to 130” lengthwise with a 50” width and that includes the installation of a fan. Most available larger and cheaper panels are approx. 60” x 40”; where two pv panels would suffice, no room is left for the fan.
A better solution is four 47” x 22” photovoltaic panels from AMSolar or equivalent, that occupies about 90” of the roof, with plenty left for a fan. A consequence is the lower voltage rating of these panels of about 18 volts, which reduces the benefit of a MPPT controller.
Inverter
With the planned propane cooktop and heater, a small 300W pure sine inverter is more than sufficient to power small loads, like a printer or scanner. Most small appliances, such as laptop and cellphone, that are ordinarily charged on 110V, will all have their own more efficient 12V inverter.
Note:
While finishing the multi-use cabinet, the idea of installing an induction cooktop developed as a possible alternative. I have been cooking with induction for years now and the advantages over gas are great. Extremely safe and efficient. With a different solution for heating, I could eliminate the proposed undercarriage, propane tank.
One obstacle is the power it requires to operate. Research on the different forums, leaves the issue unresolved. To experiment with induction, a larger 1000W-1500W inverter is required.
RV Photovoltaic System Schematic
The calculated size of the battery bank, the number and size of the solar panels and the other derived equipment are all comprised into this simple diagram.
Click on the image, for a larger view.