In general, the higher the price, the more light that will be delivered for a longer amount of time. All residential solar lighting products use energy-efficient LEDs which can provide a sharp, narrow beam of light or a soft, diffused glow. Unlike incandescent bulbs or compact fluorescent bulbs, these low-energy lights do not radiate as much light.
It's hard to tell how long a given charge will last, but the amount of time a solar light will stay on depends on the size of the battery, the size of the solar panel and the amount of available sunlight.
The convenience of solar lights is that they can be placed outdoors, and do not require an electrical socket. However, the solar cells need to be positioned in bright sunlight to allow for the batteries to charge to their fullest during the day. The efficiency of a solar panel can be reduced up to 90% by indirect sunlight or when obstacles cast shadows on the cells. This can cause the lights to go out much earlier during the night.
Buy a light that's specifically made for your intended purpose. For instance, pathway or garden lighting should be rugged enough to take the full blast from a sprinkler. Flood lights are usually placed at a base of a fountain or yard ornament and should be tough enough to take runoff and dirt. Solar power Christmas lights should be able to withstand cold temperatures and ice. Solar power post caps are specifically made to perch atop deck and fence posts.
Solar power lights are inexpensive enhancements that are easy to install in any yard. With so many types to choose from, there's sure to be one that fits your needs.