Calculation formula for the configuration of led road lighting

　　One: First calculate the current:

　　Such as: 12V battery system; 2 30W lamps, a tal of 60 watts.

　　Current=60W÷12V=5A

　　Two: Calculate the battery capacity requirement:

　　For example, the accumulated lighting time of street lights every night needs  be 7 hours (h) of full load; (such as turning on at 8:00 in the evening, turning off 1 channel at 11:30 in the evening, turning on 2 channels at 4:30 in the morning, and turning off at 5:30 in the morning)

　　Need  meet the lighting needs of continuous rainy days for 5 days. (5 days plus the lighting of the night before rainy days, taling 6 days)

　　Srage battery=5A×7h×(5+1) days=5A×42h=210AH

　　In addition, in order  prevent the battery from overcharging and over-discharging, the battery is generally charged  about 90%; about 20% is left for discharge. So [FS:PAGE]210AH is only about 70% of the real standard in the application.

　　Three: Calculate the peak demand (WP) of solar panels:

　　The cumulative lighting time of led street lights needs  be 7 hours (h) per night;

　　★: The solar panels receive an average of 4.5 hours (h) of effective light per day; at least relax the 20% reserve for solar panels.

　　WP÷17.4V=(5A×7h×120%)÷4.5h

　　WP÷17.4V=9.33

　　WP=162(W)

　　★: The daily sunshine time of 4.5h is the sunshine coefficient in the vicinity of the middle and lower reaches of the Yangtze River. The middle and upper reaches of the Yangtze River are generally 5h.

　　In addition, in solar street lamp components, the line loss, the loss of the controller, and the power consumption of the ballast or constant current source are different. In actual applications, it may be about 5%-25%. So 162W is only a theoretical value, and it needs  be increased according  actual conditions.