Calculating Formula of Solar Street Lamp Configuration
一：首先计算出电流：
Firstly, the current is calculated.
如：12V蓄电池系统；30W的灯2只，共60瓦。
Such as: 12V battery system; 30W lamp 2, a total of 60 watts.
电流＝60W÷12V＝5A
Current = 60W_12V = 5A
二：计算出蓄电池容量需求：
Second: Calculate the battery capacity requirements:
如：路灯每夜累计照明时间需要为满负载7小时（h）；
For example, the cumulative lighting time of street lamps per night should be 7 hours (h) of full load.
（如晚上8：00开启，夜11：30关闭1路，凌晨4：30开启2路，凌晨5：30关闭）
(If it opens at 8:00 p.m., closes Road 1 at 11:30 p.m., opens Road 2 at 4:30 a.m., and closes at 5:30 a.m.)
需要满足连续阴雨天5天的照明需求。（5天另加阴雨天前一夜的照明，计6天）
It is necessary to meet the lighting requirement of 5 consecutive rainy days. (5 days plus overnight lighting on rainy day for 6 days)
蓄电池＝5A×7h×（5＋1）天＝5A×42h＝210AH
Battery=5A*7h*5+1 days=5A*42h=210AH
另外为了防止蓄电池过充和过放，蓄电池一般充电到90％左右；放电余留20％左右。所以[FS:PAGE]210AH也只是应用中真正标准的70％左右。
In addition, in order to prevent the battery from overcharging and overdischarging, the battery is generally charged to about 90%, and the remaining discharging is about 20%. So [FS: PAGE] 210AH is only about 70% of the real standard in application.
三：计算出电池板的需求峰值（WP）：
Third: Calculate the peak demand of battery panel (WP):
路灯每夜累计照明时间需要为7小时（h）；
The cumulative lighting time of street lamps per night is 7 hours (h).
★：电池板平均每天接受有效光照时间为4.5小时（h）；最少放宽对电池板需求20％的预留额。
: The average daily effective illumination time for the panels is 4.5 hours (h); at least the 20% reserve for the requirements of the panels should be relaxed.
WP÷17.4V＝（5A×7h×120％）÷4.5h
WP_17.4V=(5A*7h*120%) and_4.5h
WP÷17.4V＝9.33
WP_17.4V=9.33
WP＝162（W）
WP = 162 (W)
★：4.5h每天光照时间为长江中下游附近地区日照系数。长江中上游一般为5h。
: The daily sunshine time of 4.5 hours is the sunshine coefficient near the middle and lower reaches of the Yangtze River. The upper and middle reaches of the Yangtze River are generally 5 hours.
另外在太阳能路灯组件中，线损、控制器的损耗、及镇流器或恒流源的功耗各有不同，实际应用中可能在5％-25％左右。所以162W也只是理论值，根据实际情况需要有所增加。
In addition, in the solar street lamp module, line loss, controller loss, and power consumption of ballast or constant current source are different, which may be about 5% - 25% in practical application. So 162W is only a theoretical value, which needs to be increased according to the actual situation.