In this post, I thought it might help some of you to know a little known fact about power inverters. I’ll try to keep it short today so I’ll get right to it. All power inverters draw power even when you don’t have anything plugged into them. I’ll bet you didn’t realize that, did you? If you don’t believe me, just open up the manual for your power inverter and in the specifications section you’ll find out how many amps are being consumed by your inverter when you think it is sleeping.
Just having your power inverter connected to your battery bank and turned on consumes electricity. This is often referred to as the “no load current draw”. Now, depending on how “smart” your inverter is, it may use less power than others during these idle times. One power inverter I owned consumed as much as 1.5 amps at idle. Owning that unit was like having a big hole in my battery bank that was constantly leaking 15 watts of electricity!
There are some things that you can do to minimize this phantom load on your batteries. One of them is to buy a model that is designed not to use much power when no devices are turned on and drawing electricity from it. Another solution is to buy an inverter that has a remote switch.
For our little off the gird cabin we simply turn the inverter off when we’re not using it. There’s no sense wasting power when you don’t need to. We have a few DC lights that are wired directly to our battery bank so that when the inverter is turned off, we’ll still have lighting in the house.
We’ve found that if we’re not watching television, there’s often no reason for us to have the inverter even turned on. Our current inverter has a no load draw of about .5 amps (6 watts) so it doesn’t leak too much power but the way we look at it, every little bit helps. Another advantage to switching your inverter off when you don’t need it is that it will last longer.
Nearly all power inverters have cooling fans in them that constantly spin to keep their circuits cool. Our experience has been that the bearings in these little fans are usually one of the first things to go out when an inverter starts to get some age on it. We’ve owned a couple of inverters that would start making a squealing noise at the fan and not long after that, the fans failed which caused the inverter to overheat and die.
The next time you’re in the market for one of these gadgets, take a close look at the specs sheet to find out what the no load power draw is. You might just find out that the smoking hot deal on the price may not seem so hot when you realize how much power would be leaking out of the device if you were to buy it.
If you would like to learn more about these gadgets, I suggest that you read my article called What Is A Power Inverter and How Is it Used?.