... electrical surge,short circuit,feedback,overload and other phenomena for system.This power system has high work efficiency,small dimension,good work stability ... 12hours/day Guarantee 12 hours lighting per day ,lasts for 5-7 days.Guarantee and life span:Part Guarantee ... years 15 yearsLED lamp 5 years 25 yearsCertificate: whole system -- CE,parts -- CE,ICE,UL Hybrid Wind and Solar Power Street Lights