1,TUV,UL,CE,ISO CERTIFICATE 2,OVER 30 YEARS LIFE 3,WORKING VOLTAGE: 36V 4,WORKING CURRENT: 5A ... Life Time:25 yearsControllerOver-charging and over-discharging protection. Short-circuit protection Life time : 10 yearsBattery17AH/12VDC Acid Deep Cycle Battery ... location people use 10 hrs/days ,2-3 rainy days 30 watt solar system