Upgraded Watt Power Meter Plug Home Electrical Usage Monitor Consumption, Energy Voltage Amps Kill Tester with Backlight, Overload Protection, 7 Modes Display

Before getting started, you need to understand the outdated and counter-productive method that U.S. electrical utilities use to calculate your bill. There are two components to electric power. They are the resistive component and the reactive component. Your household electric meter only measures the resistive component. That doesn't mean you're getting a partial free ride. The electric company inflates its kilowatt-hour rate to cover the community's use of reactive power. Said differently, your use of reactive power is NOT individually measured.One of the many problems with this method is that there's no incentive for modernization. If you have purchased newer and better made appliances, you're using less reactive power than the community average and are subsidizing your community. Conversely, a household with the oldest and lowest quality appliances is being subsidized by the community. This is very different from Europe where reactive power is individually measured and billed.If interested, read the article about "power factor" on Wikipedia. It's a deep dive.The point of all this is that your appliances with motors or electronics need more continuous power from a generator than you think. We forget about reactive power when we're plugged into the grid. Reactive power doesn't show up at the meter; it's built into the rate. But when the power goes out, you are your own electrical company. Your generator needs to supply all of the resistive and reactive power your appliances need to run or they just won't run.Here's a concrete example. My furnace is a very simple gas fired steam boiler. It's just a transformer, a gas solenoid, a small ignition fan motor, and a motor solenoid.The first panel on this meter tells me that the furnace draws 88 watts when running. However, that's only the resistive component, not the total power needed to run the furnace. In other words, this measurement of watts from the first panel is accurately duplicating the electric company's power meter. This 88 watts is what I would use to figure out what the electric company charges for each hour of use. In one hour, I use 0.088 kilowatt-hours at a rate of 42 cents per kilowatt-hour. So, I'm paying 3.7 cents per hour whenever the furnace is running.I would use the meter differently when sizing a generator because I want to know the total power draw. Go in by three more display panels and you'll see a number at the bottom for power factor. Power factor is a dimensionless fraction that ranges between zero (the worst) and one (the best). My furnace's power factor is 0.4. So, I divide the wattage from the first display panel (88 watts) by the power factor from the fourth panel (0.4) to yield 220 watts. That's what it takes for a generator to actually run my furnace: 220 watts, not 88 watts.The take-home message is that the rated wattage of an appliance can greatly understate the amount of power a generator needs to provide during an outage. This will be especially true for air conditioners.My little Champion generator can provide up to 750 watts while remaining very quiet. So, now I know that I can realistically expect to run my furnace on my generator. I also know that I can't run the furnace off of an inverter plugged into my car's cigarette lighter. A car's DC power outlet is generally limited to 120 watts. The furnace's rated draw of 88 watts makes this look feasible, but the reality is that the actual draw of 220 watts will quickly blow the DC outlet's fuse.This meter also tells me that my furnace draws only 12 watts at idle, but with an abysmally low power factor of 0.17. Divide 12 watts by 0.17 to get 70.6 watts. This would be important information if I wanted to run my furnace at night off of a solar panel with a battery. The battery capacity would have to be sized to accommodate a constant drain of 70.6 watts even when the furnace is idle. Twelve hours of idle time would require nearly 850 watt-hours of battery capacity, and that's a pretty large battery.To summarize, individually rate every appliance you need during an outage by dividing the displayed wattage by the power factor. Add up the individual appliances to get a total. Then realistically de-rate your generator's listed capacity to a point where it's running quietly and reliably. My little generator is rated by the manufacturer for 1,750 continuous watts but that's when it's screaming and threatening to throw bolts. Testing with this meter has proven that 750 watts is a quiet and practical limit. Compare the two ratings to see if your generator is adequate or needs to get upsized. An advantage of this method is that you will be able to run your generator in Eco mode and will have adequate starting capacity.

This meter shows you all the data about the power the device that is plugged in. The backlight feature could be changed. it times out and turns off. I would like it to have its own on / off switch. The display is almost impossible to read without the backlight on.The menu key toggles though all the functions, and turns on the backlight.

Pretty cool. It does jump around a lot when reporting wattage, but that may just be the nature of the beast - how stable the item(s) is/are being tested.I just take an avg from it or use the highest reading.

Works great, look at your electric bill and set the amount per kwh on this device. Plug in your electric item and see how much it costs you to run. I used it on a fan and let it run 8 hours, multiply that by 3 for 24 hours.... it costs me 20.00 a month to run this thing.

Got a pair of these to use for monitoring/measuring wattage consumption for various appliances and devices in our house, prior to having a generator switch installed in our house.In order to determine the branches to power through the generator switch box and how much each branch will consume for the total wattage and capacity of our generator, these two plug in monitors are proving to be worth their weight in gold!The display is crisp, the text sharp and easy to read and the backlight display, when needed, is a huge plus. The assorted options available for settings and view of volts, amps, watts, watt-hours, electrical cost factor, etc, are also excellent.Delighted with these and I might be ordering one more to monitor another major appliance we'd be using during a power-outage and generator use.My only regret is not being able to monitor 240 volt appliances like our oven/range and dryer, but, I'm searching for one specifically for this and if they're available, I'll consider getting one of those as well.As for these wattage monitors, delighted with their performance and the reasonable cost per unit. 5 Stars all around!

Super helpful and works with 240v (euro) as well. Measures accumulated kWh and show max wattage spikes. I bought a 2nd one

Unit seems to work as described I'll have to use it more to tell how good it is.

TL;DR: To test the accuracy of your power meter, test it on an appliance or device that will have consistent power consumption while running, like a lamp or a kettle. For example, the information on the base of my kettle (underneath) reads 110-120V 50/60Hz 900-1100W. When I ran the kettle through the meter it read 123 Volts, 60Hz, 9 Amps, and 1100W. That tells me that the meter is operating correctly (the kettle, too).Not an electrician here, but I read about a potential problem with the accuracy of these meters; that the manufacturer might have made a mistake with the programming for the Watts reading on the meter. For example, in general, Volts x Amps should should give the Watts used by an appliance/device, but the Watts reading on the meter when I was running a test on my laptop didn't seem to make sense. When I multiplied Volts x Amps (from the meter's reading) the result (in Watts) did not match the Watts reading on the meter. The Watts reading on the meter was up and down quite drastically, partly due to whether or not the laptop was idle, or if I was scrolling, or playing a video, etc. Running the test on the kettle let me know that the meter is probably accurate, and that my understanding of my laptop's power consumption is limited! Also, multiplying the Volts x Amps for the kettle (while it was running) was correct -- around 1100 Watts.