300W Pure Sine Power Inverter (12V)

When calculating the max current draw when connected to a battery you divide the inverter wattage by the nominal battery voltage and then by the Inverter efficiency (we will use an average of 85% in example). E.g. If a 1000W inverter is connected to a 12V battery bank, the maximum current draw (when inverter fully loaded) will be 1000 (Watts) / 12 (Volts) / 0.85 (efficiency) = 98.0 Amps. Be sure to check the size and configuration of your battery bank and what the max current draw of the battery is to avoid damage to your battery.

The test leads included allow you to connect and use the inverter straight out of the box as a temporary solution. When mounting the inverter in its location you need to size the cables according to the distance and loading of the inverter. There are many DC Cable Size Calculators available online to help you size cable between the inverter and battery bank.

This is the amount of power the inverter can sustain, but only for a very short period of time. Some appliances, particularly those with electric motors need a much higher startup surge than they do when running. The surge at its maximum will typically last for 20-50 milliseconds so the inverter does not go into overload and shutdown, the surge time period increases depending on % over the inverters nominal power rating.

The easiest way to do this is just multiply the battery voltage and fuse current rating (V x I). If your vehicle power source (cigar socket) is 12V and fuse rating is 30 Amps, you multiply these to calculate Power. E.g. 12 (volts) x 30 (amps) = 360 (watts)