FAQ

When choosing batteries for your battery bank, you should consider two things; what you are running and how long you want to run your system? 

Now you can take the output AC amps multiply them by the volts output (vac) to figure watts.  Then, watts divided by input volts (vdc) gives the DC amps consumed per hour.  Once you have your DC amps per hour, you need to include the power loss through the inversion, which is about 10%.  Generally you should just multiply your DC amps per hour by 1.1 and this will give you the right amount in your final DC amps required total.

Amps ac (your load) x Volts ac = Watts

Watts/Voltage dc = Amps dc per hour required

Amps dc per hour  x  1.1 = actual Amps dc

Determine Continuous Load and Starting (Peak) Load: You need to determine how much power your tool or appliance (or combination of them that you would use at the same time) requires to start up (starting load), and also the continued running requirements (continuous load).

What is meant by the terms "continuous-2000 watts" and "peak surge-4000 watts" is that some appliances or tools, such as ones with a motor, require an initial surge of power to start up ("starting load" or "peak load"). Once started, the tool or appliance requires less power to continue to operate ("continuous load")

Helpful formulas: 
To Convert AMPS to WATTS:
Multiply: AMPS * AC (voltage) * η (efficiency of Inverter) = WATTS 
This formula yields a close approximation of the continuous load of the appliance 
To calculate approximate Startup Load:
Multiply: WATTS * 2 = Starting Load
This formula yields a close approximation of the starting load of the appliance, though some may require an even greater starting load.

NOTE: Induction motors such as air conditioners, refrigerators, freezers and pumps may have a start up surge of 3 to 7 times the continuous rating.

Most often the start up load of the appliance or power tool determines whether an inverter has the capability to power it.

An UPS typically includes the battery and battery charger in one stand-alone unit. The input voltage window for UPS is comparatively less than that of inverter. However, there are UPS systems that use external batteries, and Power Stream makes inverters with battery chargers, so the differences blur as features proliferate.

Yes, you can. All appropriate rating inverters can easily and safely supply power to a computer. In fact the output voltage from an inverter is often better than that from the electricity grid.

Some inexpensive stereos use power supplies that cannot eliminate common-mode noise. These would require a sine wave inverter to operate noise-free.

An inverter is a DC powered device that takes DC power (battery or solar, for example) and converts it into AC "household" power for running electronics/electrical equipment and appliances.