Solar is the rage these days and prices continue to drop to utilize the technology. If you intend to do this, I would suggest a multi layer approach. Use a battery isolator or battery switch so that a deep cycle second battery can be installed. By doing this, you prevent the main engine battery from being discharged(the battery that gets ya home), and the deep cycle can take the deep discharges that occur with high power accessories like stereo's, trolling motors, refrigerators, etc. Then a solar cell can be added with a solar charging unit to charge the accessory battery or both. This would extend your time by allowing some energy to be put back in. Do not expect a solar panel to adequately operate even low power accessories directly, some form of energy storage must be utilized. Turn key systems are available for this purpose, or you can design your own, lots of info on the web. Good luck. Michael.
