How to detect the life of solar street light source

In order to ensure the lighting time of solar street lights, most of them use LED light sources to provide lighting, but the junction temperature is an important factor affecting the attenuation of LED street lights. The rise in junction temperature will cause the LED light to decay quickly. The LED light source will generate more heat when working at high current, which will accelerate aging. Using different driving currents, select 5 LED street lamps, and perform accelerated life tests with different currents at an ambient temperature of 25 °C, and get the light output attenuation. Mathematical model: yu003dexp(-αt) where αu003dm×exp(nI), y is the relative light output, α is the decay constant, t is the lighting time, m and n are constants, and I is the test current. According to the test data about y and t obtained under different currents, the attenuation coefficient α of different lamps is finally obtained, so as to obtain the life value of the luminous flux maintenance rate of 70%. Using the temperature as the constant acceleration stress, the expected life of the LED lamps when the failure criterion is 70% at 25°C is calculated. Five LED street lamps of the same specification are selected, and the temperature of the oven is adjusted, respectively at 50°C, 80°C, and 100°C. , 120°C, 150°C, with rated current and constant current as constant acceleration conditions, record all parameters of 5 groups of LED reliability test process: light output (illuminance or luminous intensity or luminous flux), test time, current, power, junction temperature, etc., so that the failure judgment at 25 ℃ is 70% of the expected life.