Key Features & Benefits Boost and Buck TRUE AVR for Voltage Stabilization - automatically regulating and smoothing the power supply from voltage fluctuations (140-300V) to better protect your equipment with a constant voltage. Fast charging - gain 90% capacity after 4-6hours of recharging Off-mode Charging and Cold Start Function - PRO1200SV only Cold Start Function (DC power on) and Off-mode Charging - PRO1200SVU only Wide Input Voltage range and compatible with small generators