Solar Power for RV, Boats and Campers | Convenience & Savings

The commercializing of solar power has opened up new horizons for RV and Camper users. Converting your RV to a solar battery charging system can give you a far wider variety of choices of destinations without having to worry about electrical connections. The other great advantage of a solar system is that it is clean and silent - no noisy generator working away in the background. There are a few points that you should give thought to before committing yourself to any one system.

The batteries you use in an RV suffer far greater climate change than those you would find in a solar powered house. This can lead to deterioration or excess water loss if not taken into account. To be fully charged, a lead-acid battery needs to be pushed to its gassing threshold - this is reached when the charging voltage is about 14-volts and will differ depending on the temperature of the battery. When drawing up the system you need to choose a charge controller that includes battery temperature compensation.

Solar panels placed on the flat roof of an RV operate at higher temperatures than normal, and as their temperature rises so the voltage output drops. A solar panel can reach temperatures of 150ºF in the hot sun, and when this occurs there can be a voltage drop of 2 volts. If you have a solar panel that is rated at 14-volts at this kind of temperature, it will only produce about 12 volts output - not enough to charge your batteries. You should therefore consider choosing a panel with a rated output of a minimum of 17-volts, though 20-volts is better still. Poly-Crystalline panels are probably the best bet as they take up less roof space - if looked after they should operate with no hitches for over 30 years.

The charge controller is the next very important item. Gone are the days of the straightforward charger, which is either off or on. Look for a controller that has tapered PWM (pulse width modulation) coupled with temperature compensation. This type of controller tracks the maximum current to send to your batteries and will keep them at the best charge without using too much water.

In order to determine how many solar panels you need, you must first work out how many amp-hours of energy you use on the average day - let us say the value is 40 amp-hours. A 90-watt panel produces about 5 amps in full sunlight, or 30 amp-hours in 6 hours of full sunlight - you would therefore need two 90-watt panels.

In conclusion - don't go out and buy the first unit you see, rather take your time and give it lots of thought. There are plenty of systems for RVs and Campers out there, so establish your needs and shop around.