The first method: Use a DC clamp meter to test the current and voltage of the light source, and multiply the two to calculate the power. This is also the simplest method. The second method: Calculate using solar panels: Reverse the power of solar panels: The actual power of the light source = solar panel power x peak sunshine hours / light source full power working time / 2.22. The third method is to calculate using lithium battery capacity: The actual power of the light source = battery capacity x battery voltage / 2.22 / light source full power working time.

The actual power of solar street lights is constantly changing. No matter which method we use, we can only calculate a rough actual power, which is basically equivalent to the average power of solar street lights during high brightness hours. Therefore, this value is also very reference.
Why the actual power of solar street lights keeps changing
1 Before leaving the factory, most solar street lights are set to 3-6 power outputs
Take overnight operation as an example, the most common setting method is as follows:
High brightness period (2-4 hours): 1 hour 100% brightness + 2 hours 60%-70% brightness
Second brightness period (1-2 hours): 2 hours 40% brightness
Low brightness period (6-7 hours): 6 hours 10% brightness
Second brightness period (1-2 hours): 2 hours 30-40% brightness
In this way, the full power working time of the street light is about 4.5 hours. Of course, according to the working time required by the customer, the full power working time set by each configuration will be different. For those with less configuration, the lights are on all night, and the full power working time is only 3.5-4 hours.
2 Automatic power reduction function of the controller
Every time the controller discharges, it will automatically increase or decrease the output power based on the set data (maximum not exceeding the set value) according to the battery voltage.

Method 1 for calculating the actual power of solar street lights: clamp meter measurement method
If you happen to have a programming remote control that matches this set of solar street light controllers, you can directly know the actual power of the solar street light by reading the parameters. However, end users generally do not have programmers, but DC clamp meters can be purchased. Why use a clamp meter? Because it is more convenient to measure current with a clamp meter, and it is more troublesome to measure current with a multimeter. However, it must be a clamp meter that can measure DC current, and pay attention to the current range value of the test. The test steps are as follows:
1. Fully charge the battery
2. Disconnect the charging cable and enter the discharge mode
3. Test the line end of the controller connected to the light source
4. Test the voltage and current
5. Calculate the actual power of the solar street light
The clamp meter measurement method is the simplest and most direct method. It is also the method recommended by Mr. Li among the three methods for calculating the actual power of solar street lights. If you are more patient and measure it every hour, you can also measure how the manufacturer sets the power of the solar street light.

Method 2 for calculating the actual power of solar street lights: battery capacity reverse method
The premise of this method is that the discharge depth of the lithium battery is controlled at 50%, that is, the battery power is used up in 2 days, which means 2 absolute rainy days. Some solar street lights on the market use up all the battery power on the same day, which we do not recommend. Continuous deep cycling every day has a great impact on battery life. There are also some that use up the battery power in 3 days. However, due to cost reasons, most of them are used up in 2 days, and different days can be changed accordingly.
Therefore, battery power (WH) = actual power of solar street lights x full power working time x2/discharge depth (90% for lithium batteries)
Battery capacity (AH) = WH/V
So: actual power of light source = battery capacity x battery voltage/2.22/full power working time of light source

Method 3 for calculating the actual power of solar street lights: reverse method of solar panel power
The reverse method of solar panel reverse solar street light actual power is based on: daily power generation of solar panels = daily power consumption of light sources.
Solar panel power generation per day = solar panel power x peak sunshine hours / 2.22
Light source power consumption per day = solar street light actual power x full power working time
[Note] 2.22 is the coefficient calculated from the coulomb efficiency of the battery and the charging efficiency of the solar panel. This system is different for different voltage systems.  The controller conversion efficiency is not calculated.
The calculation formula is: actual power of light source = solar panel power x peak sunshine hours / full power working time of light source / 2.22