Poorly designed solar lights that work fine during the 13 hour cloudless days and 11 hour nights, might not work at all in December when the days are short and the nights are long after a string of cloudy days. That is a big advantage to the customer, but the charge process of such batteries requires precision control. This is why Solar Outdoor Lighting, Inc. uses a proprietary charge controller proven by years of field experience to extend the life of batteries far beyond their normal manufacturer's warranty. Unlike automobile headlights which use 12 volt bulbs, Solar Outdoor Lights employ fluorescents or low pressure sodium bulbs which deliver much more light for the same wattage and are much longer lasting than 12 volt incandescent bulbs. This is one reason why Solar Outdoor Lights with fluorescent bulbs must have Underwriters' Listing.
Solar lights use batteries many times as powerful as automobile batteries.
Another reason for Underwriters' Listing. By reviewing product specifications carefully, and talking with customers who have experience with these products longer than the seller's warranty period. SOL's basic warranty for all components and workmanship is two years. Included in the basic warranty are also three additional years for the controller, for a total of 5 years. Extended warranties for the battery and other components are available at nominal cost.