Home & Office
Why you can trust ZDNET : ZDNET independently tests and researches products to bring you our best recommendations and advice. When you buy through our links, we may earn a commission. Our process

'ZDNET Recommends': What exactly does it mean?

ZDNET's recommendations are based on many hours of testing, research, and comparison shopping. We gather data from the best available sources, including vendor and retailer listings as well as other relevant and independent reviews sites. And we pore over customer reviews to find out what matters to real people who already own and use the products and services we’re assessing.

When you click through from our site to a retailer and buy a product or service, we may earn affiliate commissions. This helps support our work, but does not affect what we cover or how, and it does not affect the price you pay. Neither ZDNET nor the author are compensated for these independent reviews. Indeed, we follow strict guidelines that ensure our editorial content is never influenced by advertisers.

ZDNET's editorial team writes on behalf of you, our reader. Our goal is to deliver the most accurate information and the most knowledgeable advice possible in order to help you make smarter buying decisions on tech gear and a wide array of products and services. Our editors thoroughly review and fact-check every article to ensure that our content meets the highest standards. If we have made an error or published misleading information, we will correct or clarify the article. If you see inaccuracies in our content, please report the mistake via this form.


What I use to measure device power consumption (and what you should use instead)

This is another one of those 'Do as I say, not as I do' moments.
Written by Adrian Kingsley-Hughes, Senior Contributing Editor
Home Electricity Usage Monitor
Home Electricity Usage Monitor
Home Electricity Usage Monitor
View now View at Amazon
The Hopi HP-9800 power meter

The Hopi HP-9800 power meter.

Adrian Kingsley-Hughes/ZDNET

As part of my work, I test a lot of devices that are mains-powered (or wall-powered), and one of the tests I carry out is power consumption. I've had a lot of questions about the devices I use for this task, so here I'll outline the tools I use, why I use then, why you probably shouldn't use them, and what you should use instead.

There are a lot of different tools you can buy for measuing power consumption, ranging from very cheap to very expensive.

Also: The best power banks for recharging your devices

A few years ago, I picked up a Hopi HP-9800 meter from eBay. Its price ranges $50 to $70 (the cost seems to fluctuate daily), and while it's now put in a few years of service, from a safety point of view, it's a bit… lacking.

The socket -- which is the type that accepts all sorts of plugs -- features metalwork, which is live at mains voltage that could easily be touched, along with speaker connectors that have been repurposed as connectors that also have exposed bits live at mains voltage.

You could stick your fingers in here and touch live voltage

You could stick your fingers in here and touch live voltage.

Adrian Kingsley-Hughes/ZDNET
These bits of metal are live at a quarter of a thousand volts

These bits of metal are live at a quarter of a thousand volts.

Adrian Kingsley-Hughes/ZDNET

Those speaker connectors also make it near impossible to fit a U.K. plug, so I have to use an adapter.

Some plugs don't fit properly!

Some plugs don't fit properly.

Adrian Kingsley-Hughes/ZDNET

But I know the nature of the beast, take care when I'm using it, and unplug the device when done. One big plus point: that display is nice and clear, and easy to read (although a bit flickery when viewed through a camera).

Nice, clear display on the Hopi HP-9800

Nice, clear display on the Hopi HP-9800.

Adrian Kingsley-Hughes/ZDNET

The other day, I came across a new meter called the AnTai ATX.9801.

The AnTai ATX.9801 power meter

The AnTai ATX.9801 power meter.

Adrian Kingsley-Hughes/ZDNET

I picked this tool up from AliExpress for around $50, and while it's visually similar to the Hopi unit (I'm not sure if it's an upgraded version, a clone, the original product, or something else), this device seems to be an upgrade. 

Also: The best portable power stations you can buy

I find this unit works more reliably with some loads, and is much better from a safety point of view. For example, the socket has covers over the live metalwork, and the speaker connectors off the front are gone.

Shuttered safety socket on the AnTai ATX.9801

Shuttered safety socket on the AnTai ATX.9801.

Adrian Kingsley-Hughes/ZDNET

Again, it has a nice, clear display.

Nice, clear display on the AnTai ATX.9801

Nice, clear display on the AnTai ATX.9801.

Adrian Kingsley-Hughes/ZDNET

It's a good unit -- but, once again, it's not something I'd leave plugged in unattended.

A much better option for most home users is a plug-in power meter. 

Also: My favorite power bank for my MacBook Pro gets an upgrade

There are a lot of them on the market, and you can pick up a decent one for $15. I've tried and tested this one and it seems to do it all, including measuring power (W), energy consumption (kWh), volts, amps, power frequency, power factor, and minimum and maximum power usage (W). 

And if you input how much your electricity costs per kWh, then this unit will show you real-time data on how much something is costing you to run.

Home Electricity Usage Monitor
Adrian Kingsley-Hughes/ZDNET

This unit does it all -- it measures power (W), energy (kWh), volts, amps, hertz, power factor, cost, and minimum and maximum power (W).

This meter also has additional features, such as overload protection and even a memory that retains power consumption data when unplugged. It's a really good all-round power meter. It's a great unit, and much safer for home users.

So, why do I continue to use my sketchy power meters? Bottom line is convenience -- these units show everything I need to see on the display at once, without me needing to press buttons or flick between screens, and the socket will take anything I plug into it (as long as it's not my fingers). 

Editorial standards