I bought a Giandel 24V / 120V 2000W pure sinewave inverter, and I have been having trouble with low voltage AC output as low as 90 VAC. I first noticed that it had difficulty running my microwave during testing. Then, when I plugged my refrigerator in during a power outage, the compressor wouldn't start (!). I have been e-mailing their tech support, and they seem to think it is a humidity problem. They told me to heat the insides with a hair dryer. That helped some, but I am getting between about 98 - 105 VAC out. I think these folks are based out of Australia where they don't have the sort of humidity that I have in Arkansas. I'm using it inside my garage, which isn't dripping wet, but it is more humid than inside my air conditioned house. We did have a tropical storm blow through which made things quite humid for 2-3 days. I looked inside for any type of trim pot adjustment for voltage. I found one crude pot, but tweaking it slightly didn't seem to have an effect. Next thing I'm going to try is to remove the cover and put my dehydrator motor/heater directly on the heater, and leave it there for a couple of hours. If that doesn't work I will be talking to them about a return. . .