Originally Posted by Gregg Willow
"Power ratings are grossly over-stated. I have owned this product for about 1 year. It has worked great for powering my laptop while in the car. I have not been able to get it to supply power any greater than 100W without it shutting off however. With the inverter connected directly to clean battery terminals with the included battery clamps, vehicle running (14+ volts at clamps), I have unsuccessfully tried powering two different TV's rated at 140W. In both instances the inverter shut off when the TV's where powered on. I next tried turning on a 150W halogen flood lamp. The inverter shut down before the lamp lit. This inverter is rated at 400W RMS/800W peak. It should be able to supply these loads without any issues. Keep in mind I tried these loads with the inverter connected directly to my (dual) truck battery, engine running. The test where run on multiple occasions. There was no lack of supply current/voltage."
Just wondering if there is any salt to this.
Here is the thing. I am sure his rant makes perfect sense from his perspective, but I can give you a reason why "his test" results could be skewed.
He does not say what size wire he used to connect the inverter to his batteries. at 150 watts (his lamp) is 150watts/12volts = 12.5 amps.
16 gauge wire is needed to avoid power loss in the incoming wires at that amp draw.
If his wires were too small, he would lose so much voltage the inverter would shut down.
How long were his leads from the battery in the running truck to the inverter? He does not say. Even wires of the correct gauge to carry that amperage need to be increased if the run is more than a few feet.
I have no reason to pick one over the other and there are several good inverters out there. (and some great ones)
Shop Power Bright 400 Watt 12V DC-AC Power Inverter at Lowes.com
You can also try a Pure Sine Inverter (plays nice with computer equipment)
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