Watts Up AC Power Meter

Want to know how much energy your refrigerator uses, just plug it in to this device. For a low price, you can check on all appliances in your house. After checking one out from our public library on many occasions, I finally bought one. I use it particularly to record how much electricity my Nissan Leaf electric car uses.

Just received the unit and was dissapointed.1) Manual says: Below 60 watts, amps and power factor accuracy degrades, but wattage is accurate down to 0.5 watts."Degrades" is an understatement and I wish I saw this in the specs. The unit doesn't even detect those values below 10 watts.2) The response time of watt measurement is extremely slow. It takes about 20 seconds before you get a stable reading.

This is an interesting device with potential, but out-of-the-box it has some serious limitations you should know about.The device has two data interfaces, mini-USB and Ethernet. All configuration of the device must be done via USB from a Windows computer (there is also a freeware Linux utility, and the protocol is documented as well). The Ethernet port appears to not accept incoming connections of any kind, it only makes outgoing connections at intervals to report its status.The reason I bought the device was its ability to turn the output socket off and on by remote control over the network. I have a flaky system that periodically needs to be hard power-cycled, and this looked like a reasonably inexpensive way to get that capability.The way the "net" feature of the device works is as follows: You configure a hostname and path to a POST script and an update interval. Each interval, it will connect to the web site configured and submit a POST request with its current status. The web server can then, if it chooses to, respond with "[1]" to turn the power off or "[0]" to turn it back on. So if you're willing to write your own custom server application to log and control the device you should (theoretically) be able to do whatever you want.By default the device posts its data to the manufacturer's web site and you can create a free account there to view the logged data and (in theory anyway) also control the power output on the device.There are a few problems with this. The "free" web account only accepts updates from the device every 15 minutes, and it will reconfigure the device back to 15m if you try to set it up faster.Because the power control is done as a response to a data post, a power cycle operation will take between 15 and 30 minutes to complete. You have to ask it to turn the power off, then wait for the next poll interval, then ask for the power to be turned back on, then wait 15 minutes for that to happen.If you wanted to have a 1 minute polling interval (reducing the time to power cycle from 30m to 2m or less) then you would have to pay $25 per month(!) for this.Also, so far the web-based power-control feature DOES NOT EVEN WORK! You ask it to turn the power off, wait as long as 15 minutes, and then it simply reports that the power is still on. The posted energy usage data comes through fine, but either the server is not sending the power off response or the device is not getting it, or is ignoring it.So, assuming (I haven't tried it yet) that writing your own server code will actually work, then this a pretty useful device I think. But if you're expecting to use it to monitor and control your device via the web, these features are fairly limited and the power control just does not work (at least so far for me).Otherwise the features are similar to any of the other (lesser) Watts Up models.

Love the size, simplicity, and ease of use. Great product to create the awareness on what it cost to run small 120v equipment loads.

Very good product. Functions as advertised. I recommend strongly!

This review is for the "Watts Up? Pro" meter. If you are looking at the regular Watts Up? meter which has the simplest feature set of the 4 models, I highly suggest looking at the Pro model instead which isn't that much more expensive, and reviewing their website to note product differences.PROS:------(1)Excellent Current Wattage, Cumulative Watt Hours, and Max/Min Watts measurement EVEN AT LOW WATTAGE (<5w, <10w) when Amp measurement error increases.Wattage is furthermore measured 2,500 times per second regardless of how frequently you choose to log. Thus Cumulative Watt Hours and Max/Min Watts figures are going to be fairly accurate regardless of your log frequency.(2)The ability to position the meter at a COMFORTABLE READ POSITION and fit the plug into tight spots is very nice.(3)It has a measurement available called POWER CYCLE which counts up each time power is lost/regained, which of course if not accounted for could greatly affect accuracy.(4)It automatically puts the information into its own built in spreadsheet making my CUT AND PASTE INTO EXCEL easy. Of course it creates a delimited text file for import, too.(5)Found the meter EASY TO LEARN AND USE, and the software took at most 5-10 minutes to learn.(6)Most expected values tracked, though most folks will perhaps be mostly interested in:- Cumulative Watt Hours- Current Watts- Power Cycle (which tracks when power went off during measurement).Others measures: Min/Max Watts, Power Factor, Volt Amp (apparent PWR), Avg Mthly Kwh, Elapsed Time, Duty Cycle, Frequency (Hz), Cumulative Cost, Avg Mthly $, Line Voltage, Min/Max Volts, Current Amps, Min/Max Amps.CONS/SUGGESTIONS:--------------------- Please add a built-in clock like most other data loggers. Right now you note down the start or end time of the sampling and enter it in the program, or just put it into your spreadsheet as I do, however, a product like this should have a built-in clock to date/time tag the log. I will raise it to 5 stars when time logging is added.- More records storage would be nice. I'd like to sample with 10 second frequency for over a week, for example.TECH SUPPORT:---------------I called twice with a few questions, their tech support was both FRIENDLY and TECHNICALLY KNOWLEDGABLE.NOTES:-------- To increase the logging points and thus the time it has to log, reduce the variety of measured values (for example, to just Cumulative Watt Hours, Current Watts, and Power Cycle).- If you didn't note it from above, the Current Watts is an instantaneous measure, it isn't using the 2,500 samples/sec data that the cumulative watts and min/max watts are using.GET TO KNOW THE OTHERWATTS PRO METERS:-------------------------I suggest reviewing all models of the Watts Up line-up on their website before choosing a model. The models are:- Watts Up?- Watts Up? Pro- Watts Up? Pro ES- Watts Up? .NetI think of the "Pro" version as a sweet spot in the line-up. There are 4 models (listed above), 1 below it and 2 above it feature-wise. I would assume anyone interested in this kind of product would want at least the "Pro"'s features.If you expect to measure power that is either (A) sourced from an inverter sometimes or (B) affected by the source or environment by extreme levels of line noise, then you probably want the ".Net" model version (or for the latter buy a line filter). It has more shielding, more strategic separation of components, etc. If you have a problem with either case you will know right away as the data will go bonkers in an obvious way, I'm told.The "Pro ES" and ".Net" models store 4x the records of a "Pro" (120,000 vs. 30,000). For example, if you wanted to only track Cumulative Watt Hours, Current Watts, and Power Cycle then you can save 40,000 data points (120,000/3). With 1,440 mins and 86,400 secs in a day, you can determine which you need. Remember that the Cumulative Watt Hours and Min/Max Watts calculation is always based on the 2,500 samples/sec no matter the logging frequency.SUMMARY:----------Highly recommend these meters if they meet your needs.