First of all, we use high-efficiency solar panels with high efficiency of 19%. In addition, we use 1W=190LM high-efficiency LEDs, which can save 100% of battery power. More importantly, we have advanced ALS technology that can prolong the lighting time to 7~10 rainy days, this ALS technology was developed by us in 2017 and got invention patent license（Certificate NO.: 201710713248.6）.