best ratio solar LED  lamp

A properly-sizedsolar light means the system has just enough solar wattage to charge the battery, and the battery has the enough energy to power the LED fixture at theprogrammed lumens   every night for manyyears—all while providing backup power to last inunpredictable weather and without adding unnecessary solar panels or batteries.It is called golden ratio:that would not cause the system died prematurelybecause of lower capacity, and far beyond the solar system to make itneedlessly expensive.

Here are three keyfactors for a properly sized, reliable solar street light depends on: a healthyarray-to-load ratio, sufficient battery capacity and backup power, and anefficient LED fixture and operating profile.all in all ,the final cost dependson how long do you want the solar lamp last and working mode ?