Solar powered battery selection is very complicated, the following is a battery design for solar street lighting system for you, hope it can help you
The following examples illustrate the main points of solar street lighting system design:
For example: a batch of solar street lights need to be installed in a certain city, the light source power is 30W, and the street lights are required to work every day
It can work for 8 hours to ensure that it can work normally in 7 consecutive rainy days. 114 degrees east longitude, 23 degrees north latitude, year
The average daily solar radiation is 3.82KW.h/m
2
, the annual average monthly temperature is 20.5 degrees, two consecutive rainy
The interval between days is 25 days.
Based on the above information, it is calculated that the inclination angle of the photovoltaic module is 26 degrees, and the standard peak time is about 3.9 hours.
(1) Load daily power consumption
Q=W* H/U=30*8/12=20Ah
where U is the nominal voltage of the system battery
(2) The charging current of the solar battery module that meets the load daily power consumption
I1=Q*1.05/h/0.85/0.9=7.04A
In the formula, 1.05 is the comprehensive loss coefficient of solar charging, battery charging efficiency, controller efficiency
3) Determination of battery capacity
The battery capacity C that can meet the normal work of 10 consecutive rainy days
C=Q*(d+1)/0.75*1.1=20*8/0.75*1.1=235Ah take 240Ah
In the formula, 0.75 is the discharge depth of the battery, and 1.1 is the safety factor of the battery
Choose two 12V120Ah batteries to form a battery pack
(4) The charging current I2 of the solar battery module that needs to restore the battery capacity after continuous rainy days
I2=C*0.75/h/D=240*0.75/3.9/25=1.85A
where 0.75 is the battery discharge depth
(5) The power of the solar cell module is (I1+I2)*18=(1.85+7.04)*18=160Wp
In the formula, 18 is the working voltage of the solar cell module
Pick 2 solar panels with a peak power of 80Wp
Post time: Dec-05-2022