This low frequency pure sine wave inverter charger is a combination of an inverter, battery charger and AC auto-transfer switch into one complete system,The overload capacity is 300% of continuous output for up to 20 seconds to reliably support tools and equipment longer. The inverter features an AC pass-through circuit, powering your home appliances from utility or generator power while charging the battery. When utility power fails, the battery backup system keeps your appliances powered until utility power is restored. When utility or generator power is restored,the inverter transfers to the AC source and recharges the batteries. The AC Priority and Battery Priority switch is SW5. When you choose battery priority, the inverter will inverting from battery despite the AC input. Only when the battery voltage is reaches low voltage alarm point , the inverter transfers to AC Input,charge battery, and switch back to battery when battery is charged full. AC Charger.The inverter is with a strong charging current of Max 120Amp and the max charge current can be adjusted from 0%-100% via a linear switch at the right of the battery type selector. This will be helpful if you are using our powerful charger on a small capacity battery bank. Appliance: circular saws, drills, grinders, sanders, buffers, weed and hedge trimmers, air compressors.computers, printers, monitors, facsimile machines, scanners.vacuum cleaners, fans, fluorescent and incandescent lights, shavers, sewing machines. coffee makers, blenders, ice markers, toasters.metal halide lamp, high pressure sodium lamp.Television.