Power meters – Buying guide & Comparison
Electrical power meters are mainly used for two things: monitoring energy consumption, both of a singular device and of an entire household, or verifying certain parameters in the electrical current that passes through a wall charger onto a device via a USB link. In both instances, they literally measure electrical power, so we’ll be taking them together in the following buying guide. If you don’t have the patience to go through it and just want to find a good device for testing the quality of chargers or cables, know that we found the Eversame CECOMINOD021477 to be very well-suited for the task. All the power meter reviews we’ve looked to gave it top marks for its wide testing range, great testing accuracy and for potentially increasing the functionality of your wall charger. For those interested in an electricity usage monitor, the P3 International P4400 should perform well, as many satisfied owners praise it for its reliability and ease of use.
You will be buying an energy usage monitor as a means of cutting down expenses. Since it would be somewhat counterproductive to spend too much on the cost-cutting device itself, you should primarily look for the best power meter for the money.
Energy usage monitors — entire output or just plug in?
There are two main types of energy monitoring power meters to choose from — units that link to the household’s electric box and measure the entire output or smaller devices that you plug in a regular socket to take measurements for an individual appliance.
The household reader can be seen as a necessity, especially if the electrical company didn’t supply you with one (which does happen in some cases). Its main downside, however, is that it can barely function as a tester for an individual appliance. While it does take accurate measurements of power, voltage, energy, you will need to plug and unplug each energy consumer in turn to get an idea of which one is responsible for the biggest drain.
The above operation is made extremely convenient by a plug in meter, which sits between the power source and the appliance, taking all relevant measurements with little risk of poor conductivity in your power cables or couplings skewing up the results.
What else to look for when buying an energy usage monitor?
In a power consumption meter, first thing after value comes functionality, which in turns allows for greater convenience.
The ability to track energy usage data over time is a very important feature to have if you plan on developing some energy saving techniques. The more the machine can save to memory, the less you will have to.
Look for a power meter with customisable measurements periods, so that readings will be taken only during the times of day you are most interested in. This will spare you a lot of sifting through unnecessary data.
Some devices allow you to calculate energy expenses at different hourly rates, which will prove useful for those living in areas where energy costs fluctuate often depending on the time of day. Energy cost might not be the same during peak hour as it is during nighttime, and the machine accounting for this difference will spare you a lot of maths.
Timeframe is not only measured in days, however, but also in weeks and months. Some units will make it easy to calculate your electricity expenses for periods upwards of a year and even factor in data like changes in prices and local tax.
It’s important to remember that an appliance’s power efficiency can’t be improved just by knowing how many Watts/h it consumes. Things such as real voltage or amps should be known in order to ensure a proper diagnosis and the quality of the power received also plays a role. Look towards devices that provide as much data as possible!
What should USB power meters have?
This is primarily a measuring and diagnoses device for wall chargers and wires, so it only has to test for current and voltage, but within very narrow parameters. Resolution is very important for a USB power meter as well as range, which adds versatility.
For convenience, look towards models that can store as many readings as possible over a relatively large span of time. Measurements should be taken in both total output as well as Watts/h and ideally presented on a multi-mode display, so they don’t clutter.
What should all power meters have?
Regardless if we’re talking about an energy monitor or a USB power meter, it’s important for the unit to take accurate readings, of more things than just Watts/h. This might not factor in as heavily for the former as for the latter, but if you plan on using the power consumption meter as something that will do more than just tell you that a problem is there, you should definitely make sure its readings aren’t off.
5 Best Power Meters (Reviews) in 2020
To help you out with your search, we have showcased a couple of power meters from each category that we believe offer the best convenience and function for their purpose.
1. Amanka USB Digital Power Meter Tester Multimeter Current and Voltage
This Eversame dual sided USB power meter is great for verifying that USB compatible tech devices (like computer power sources, wall chargers or a car chargers) put up adequate voltage and wattage for whatever it is you are plugging in.
It is more than a basic tester, however. Despite coming in a small package, roughly the size of a USB stick, it contains a rather impressive array of extra features aimed at increasing both speed and safety during charging.
It supports QC 2.0/3.0 high voltage testing, and as an added measure of safety it automatically shuts off after the charge is complete, so that more sensitive or older items that don’t do this automatically, won’t overheat.
It contains a specialized chip that accelerates the process of charging when working under higher voltage and amperage conditions, which increases its functionality to that of an item for regular use.
The Eversame USB power meter is a highly sensitive tester for volts and amps with wide testing ranges that make it good for use with basically every type of computing device and charger.
Some extra features add it greater functionality, making it usable in a number of situations.
Ensures for safety when working with older or more basic equipment by automatically shutting off the connection after the charging process is complete.
The process of charging is accelerated by taking full advantage of high voltage and amperage connections via an integrated CW3002D chip.
Its high resolution, multi-mode display can accommodate a large number of readings, presented both as total output or live as Watts or amps per hour.
The only complaint we could find about this product is that the display can be difficult to read at certain angles or in high luminosity conditions.
Click to see the price on Amazon!
2. P3 P4400 Kill A Watt Electricity Usage Monitor
Offering great convenience and functionality, this P3 International (better known as Kill-a-watt) product rises at the top of its class on most retail sites. Its use is not limited to just measuring the energy consumption of your appliances (which it does very well), but it can also test the quality of your home’s electrical installation.
It monitors line frequency and voltage shortages to let you know if your wiring is okay or if the supply from the electrical company keeps constant. It can also be used to check if outlets are in working order or to predict brownout conditions.
It’s large LCD screen displays consumption in Kw/h, but it can also show total output over a period of time, and the device has functions to calculate your energy cost over daily, weekly, monthly or yearly periods.
It is best compatible with appliances that work under the 115-125 V ranges, which gives it good usability for American households.
Besides being a great money-saving device, allowing you to calculate the energy consumption of your appliances in all ranges between peak and idle, is surprisingly affordable for the great functionality it offers.
It has a function that monitors line voltage, which lets you know when your circuits are overloaded by the addition of too many energy consuming appliances.
The amp measuring function is useful when you connect a large number of consumers with low amp fuses, such as Christmas or Halloween lights to your line.
It has a rather good sensitivity, between 0,5 to 1%, which makes it very suitable both for diagnosis purposes and “sniffing out” idle consumers.
The fact that it shows total energy consumption over-extended periods of time, up to a year, helps you greatly in calculating your electricity expenses.
According to specifications, it’s limited to 15 amps, which gives it a shorter range than some users might want.
Buy from Amazon.com for ($89)
3. Bayite AC Babyte PZEM 061 LCD Display Digital Current
The Babyte PZEM-061 is basically a household monitoring station that lets you know how much power passes through the installation, at which operating voltage and amps for AC current. With a high degree of versatility, it’s useful for both those who want to monitor their power usage in W/h and get an idea of how much they are consuming over a span of time, and also to people who are producing their own energy.
Thanks to its accurate readings of both power and energy (W/h) you can easily tell when something is wrong with your installation and it also helps you diagnose the problem by storing the last recorded data when power gets shut.
Users remark it is very easy to install but what they seem to appreciate most is its high voltage range, from 80 to 260V at frequencies of 50 – 60 HZ. It’s current meter measures between 0 to 100 amp.
Great for monitoring household energy output and consumption, it measures everything the domestic user needs to know: voltage, current (amps), total power (kW) and energy (kW/h).
Good testing ranges for voltage — which goes from 80 to 260V — and amps — 0 to 100. This gives it good versatility for a wide range of uses, and it’s especially appreciated by small energy producers, who employ it to monitor the energy output of solar panels and wind turbine.
It has a couple of functions to help diagnose potential problems and regulate energy consumption. It stores to memory the kW/h used between power applications so you might easier identify big energy consumers and it remembers power settings before shutting down.
Its monitor is backlit for easy reading in high luminosity conditions.
The most common complaint we found regards the manufacturer provided instructions being difficult to follow. This can be easily worked around by consulting the internet.
Buy from Amazon.com for ($16.98)
4. Plugable USB C Power Meter Measure Voltage Amperage
Another USB power meter, this Plugable product doesn’t have the same wide array of features as the Eversame but it is specialized for monitoring USB-C connections, which the Eversame is not.
According to the manufacturer, it’s most commonly used for testing connections between a charger and the host device (laptop, tablet, smartphone); a docking station and the host device; the host and a powered accessory (like an external hard-drive) and for testing for potential incompatibilities between the two due to causes such as VBUS hot condition or voltage drop under load.
Besides live voltage and amperage readings, it also shows you the direction the current is flowing via an arrow indicator, which makes it very useful in diagnosing potential problems between devices that work under different operational ranges.
It’s one of the few dedicated USB-C power meters on the market, which puts it in a class of its own when it comes to functionality. Basically, there’s only a choice between this and a corresponding Satchi product.
It is a more affordable and easy-to-use version of the highly regarded USBC-TKEY “Power Delivery Sniffer” from Plugable, which makes it a great choice for those that value convenience over professional-tier functionality.
The VAMETER measures voltage and power output between the ranges of 4-20V and 50 milliamps to 10 amps respectively, well within the area of all common devices it is intended for.
As a further testament to the brand’s credibility, most users report great satisfaction with the manufacturer’s customer services department.
Some users find it inconvenient that the display (although easy to read) doesn’t flip according to the side it is facing or that it switches alternatively between readings in order to prevent screen cluttering.
Click to see the price on Amazon!
5. Ensupra Electricity Usage Monitor Power Meter
The PM002 comes with all the great functionality you would expect from a newer plug-in power meter. Like any device intended to measure energy consumption, it displays a kW/h reading, but it also has a function to measure what your appliances drained away during the past 7 hours, or the past week, or the past seven months.
Its Power Factor function can give you a clue as to the efficiency of your electrical installation by automatically assessing fluctuation in your electrical input. It also has a function that automatically calculates the electricity bill for both single rate tariff and dual rate tariff regions.
For the ecologically minded, the PM002 can also calculate electric energy consumption in CO2 units, so it’s easier to know how much impact your energy usage does to the planet.
It doesn’t, however, take as many measurements as the similar unit from Kill-a-watt, so its functionality score can only be lower.
This device can help you save on the electricity bill by accurately measuring the output of household appliances at ranges varying from peak capacity to idle. Knowing how much wattage an electrical appliance requires in “idle mode” is particularly important for long term planning.
Allows for long term planning for energy saving measures, due to its function that calculates consumption over periods up to 7 months.
The unit can also calculate various parameters of interest, such as electricity cost for dual tariff areas and CO2 footprint, sparing users from the inconvenience of marking each piece of data on a separate spreadsheet.
Users seem to be satisfied with the convenience it offers. The LCD screen displays a large quantity of data at once, so you won’t have to switch between modes.
It measures a fewer number of parameters than similar products available.
Buy from Amazon.com