Next Wave 2000 VA Interactive 2*9Ah 

LED display or LCD display selectable
Microprocessor-based digital control
Boost and buck AVR for voltage stabilization
Auto sensing frequency
Wide input voltage range
Power-on self test
Cold start
Auto restart when mains power is restored
Auto track mains phase to ensure that inverter output voltage has same phase with utility voltage, reducing transfer time and peak surge
Intelligent battery management: battery temperature compensation to extend the battery life three-stage charging to shorten recharge time
Short circuit, battery overcharge / overdischarge, overload, surge protections
Automatic charging in OFF mode