The length of the solar street light, in addition to the size of the battery is related to the solar panel determines how much power can be charged in a day. So the correct choice and matching of solar panels is also very important, the following to give you on the choice of solar panels to do some explanation.
1, the solar panel must choose the correct open circuit voltage and working voltage
If you choose the PWM solar street lamp controller, to 12V storage charging, the solar panel's open-circuit voltage is generally about 20V, the working voltage is generally 17.5V. If you charge a 24V battery, the open circuit voltage and operating voltage of the solar panel are twice that of 12V.
If you choose the MPPT solar controller, the open circuit voltage of the solar panel cannot exceed the maximum input voltage of the controller.
2, solar panel power selection
Solar panel power selection, according to the company below calculation
P = Q * h/U * factor 1 / factor 2 / factor 3 * Vp
Description: Q-- load power
H-- daily service time of load
U-- system voltage
ξ1-- Number of comprehensive loss system of solar panel, taken 1.05
ξ2-- Control circuit efficiency, 0.85
ξ3-- charging and discharging efficiency of battery, 0.85
Vp-- the working voltage of solar panel
3, solar panel type, divided into single crystal and polycrystal
Single crystal solar panels are more efficient and have less light decay but are more expensive, while polycrystalline solar panels are less efficient but less expensive
4. Solar panel dimensions
There are many dimensions and specifications, and we must decide what size is more appropriate according to the installation environment of our street lamps. Generally speaking, under the same power, it is more appropriate to choose a smaller size.