Multi Protection Function: pure sine wave power inverter, 3 times surge power, up to about 9000w for several seconds. Power save model can be used when the inverter's loading is less than 20w. and it can restart automatic when it is large than 20w. Battery Charge: 3-step intelligent battery charging, float and constant charge mode, 7 battery type selector, battery charger built in, 8 Battery types: Gel U.S.A, AGM1, AGM2, Sealed lead acid, Gel Euro, Open Lead Acid, Calcium, De-Sulphatio. Battery is not included. UPS Function and USB Connector: inverter has function as UPS converter, with max transfer time of 7-13ms between battery and AC (AC to inverter