Before bying, check out the light out put (usually given in Lumens). Most of the ones I see say they use, for example, 45 watts. Watts is power used, not light emitted (lumens). Find out how many lumens of light it emits per watt. As an example, the average 100w incandescent bulb uses 100 watts of power to produce 1750 lumens. A 13w compact fluorescent , by comparison light produces 730 lumens (much more efficient). Next, check to make sure the battery will power the light long enough for the intended use. Find out how many lumens of light it emits, per watt hour (the wattage required to light the light for one hour). Obviously, make sure you have enough direct sunlight to fully charge the battery. In my experience on job sites, the newer LED's have really made remarkable strides in lumen output verses power used (watts). Sorry this was so long winded.
Greg
