Model Number: SY-8018D Brand Name: OMEGA Key Specifications/Special Features: Built-in 6V 4.5Ah rechargeable sealed lead-acid batteryWide voltage range: 110-240V, 50/60HzCharging time: 13-15 hoursUsing 9V 8W solar panel (max input: less than 8W)DC 6V output (can charge up to 4 items at one time)USB mobile phone charging function, built-in CCCVSystem to charge any mobileWhentheLEDbulbgoesdim,please chargetheproductimmediately thebattery willbeearlier damagediftheproductis charged whentheLEDbulbtotallygoesoffIftheproductwillbestoredforlongtime,please chargeitatleastonceevery3 months,andchargeover13hourseach time,otherwise thebatterylifespan willbe shortened