It doesn’t matter whether you have to choose between 2k watt power inverters or true sine wave inverters. What is important is that you know what the inverter’s maximum surge is, and how long the surge lasts.

Choose based on surge

Now when it comes to surge, all inverters have a continuous and surge rating, specified as x watts for y seconds. This means that the inverter can handle an overload of those x watts only for a short span of time.

The surge capacity is different in different inverter types and models, and is anything as little as 20% to something as high as 300%. On average, a 3 to 15 second-surges is more than enough to cover 99% of appliances. Even motors in pumps surge for only ½ second or so.

Important rules to know

Inverters with the lowest surge ratings are the highest common high-speed electronic switching type. This includes Exeltech inverters ranging from 25% to 50% maximum overload, and in the 50-5000 watt range, like 2k watt power inverters.

Highest surge ratings are transformer based, and low-frequency switchers, where the surge may reach a maximum of 300% for short periods. High-frequency switching may permit a smaller and lighter unit with reduced surge or peak capacity because smaller transformers are used.


It’s true that high-frequency switching type inverters don’t have the same surge capacity as transformer based units. However, they do offer some advantages.

For example, they are much lighter, usually smaller and even cheaper in the lower power ranges.

If you need an inverter to run something like a submersible well pump, you have to get a very high surge capacity inverter. You can oversize the inverter above its typical usage so that you know the inverter doesn’t exceed its surge rating even at maximum surge.