HOPI Meter power consumption analyzer

If you’re anything like me, chances are that you have a lot of gadgets in your home or office. But how much power are these gadgets using — and wasting? A common question is how to measure power consumption for devices. Some people are coming at this from a perspective of pure curiosity, others are looking so save money or to assess environmental impact.

If you want a reading how much your devices consume, you need some measurement hardware. A watt meter – also known as a power meter – is one of the best and simplest ways to measure how much energy your devices consume.

Trying to get accurate power measurement with an average multimeter does not usually work well and does not give accurate results. A multimeter is a vital tool, but multimeters present numerous challenges to accurately energy measurements, especially with alternating current. If you try to measure mains AC voltage and current separately and try to do the power calculations, this does not take into account Power Factor in calculations.

I have been monitoring and measuring the power consumption of gadgets for many years now and the tool I use is the HOPI HP-9800 20A energy monitor. HP-9800 is a handheld saving tester which has ability of testing the device via sustaining 20A current. I picked mine up from some Chinese shop I don’t remember anymore for under $50. This device is available from many sources. This product comes branded as Antai , HOPI , Nicetu ST-9800, and even as totally unbranded.


I first came across “the HOPI” meter when it was featured on the Big Clive YouTube channel. The HOPI is a bit rough and ready, it has things I don’t like, and it’s not “certified” in any way, but I’ve found it to be very reliable and accurate. The HOPI-9800 from Shenzhen HOPI Electronic Technology is a meter that displays the supply Voltage and frequency as well as the Amperage draw, overall power in Watts, power factor, and annual power consumption. It’s a somewhat dangerous contraption with sketchy multi-national power socket.

HP-9800 Handheld Power Meter LED Energy Saving Lamps Tester Universal USB 20A technical data:

Model: HP-9800 20A
Country/Region of Manufacture: China
Load current display range: 0.002A-20A
Active power test range: 0.5W-4400W
Power factor test range: 0.01 – 1.000
Voltage: 100V-240V AC 50/60Hz
Power consumption: less than 1W
Size: 20X 20 X 3.5cm
Weight: 800g
Features: It can meet the IEC, ANSI and JIS industry standard for measurements

The good things on HOPI is that it is pretty accurate, cheap and easy to use. Thee HOPI is little more than plug-in-and-it-works. It’s a very useful tool, and for the price offers something that is very usable. My version shows clearly the measured data on the main display (there is no connection option to log data to PC). My HP 9800 is very nice cost effective instruments and work very well. There is also version now with USB port available.

The bad things in this device is that it has no widely recognized safety certification, no good manual and the display flickers (not very visible to eye but can mess up with photography and video). The ugly details is that the electrical safety level is low: That front plug that support plugging in many kind of electrical offers very low safety. There are also two speaker-type jacks for bare wire on the front that carry live at mains voltage. Those speaker-type jacks can also block plugging in for example some UK plugs. It’s not something I’d leave plugged in unattended.

POTENTIAL DANGER: The LINE (HOT) & N (NETURAL) can get reversed when you plug devices to universal socket.

HP-9800 meter is based on power consumption measurement chip like ones used in electrical meters. It appears that the hart of HOPI this is a Cirrus Logic chip, the CS5463, product release date of April 2011.

Videos on HOPI meter:

HOPI-9800 Power Meter Review

Inside Hopi meter

Is the HOPI Energy Power Meter Tester Accurate? Let’s find out

Is it accurate

HP-9800 reviews:

HOPI HP-9800 Wattmeter

Mini review of Hopi HP-8 power meter

Few thoughts about energy meters HOPI HP9800 & HP8713 (Aug 2018)

How to measure how much power your gadgets are using — and wasting

Links to related material:

Topic: How accurate are cheap mains power meters?

How To Check Your PC’s Power Consumption [4 Methods]

How to Measure Wattage With a Multimeter

How to properly set up a multimeter to measure the power consumption of a computer?

Measuring electricity

Take Control of Your Electric Bill: How to Measure Home Power Usage

How to measure how much power your gadgets are using — and wasting


  1. Tomi Engdahl says:

    What the heck! Series capacitor makes fan go TURBO!

    I was disassembling a fan to reverse engineer its electronic humidity control and experimentally put some capacitors in series with the fan to slow it down.

    No series cap 242V 14.5W 90mA (0.66PF)
    220nF the fan struggled to turn – 95V 1.5W 22mA (0.27PF)
    470nF the fan ran at about 1/3rd the power – 157V 5.5W 51mA (0.43PF)
    1uF the fan ran at SUPER TURBO POWER! – 300V! 24W 120mA (0.8PF)

    I’m guessing I may have hit a perfect inductor/capacitor combo to result in such a dramatic result by somehow creating a phase shift that added to the supply voltage.

  2. Tomi Engdahl says:

    For those who haven’t seen the “bigclive” yt channel I present the marvel of shady and dangerous chinese electronics from AliExpress – the HOPI with its lovely live 240VAC speaker terminals. (Sorry for photo on the shiny stove, i.m using it as workbench, and the exposure time must be long due to slow multiplexing of the display). This device is unique in many ways – it contais a really advanced Cirrus Logic CS5463 smart meter chip, and inside it’s quite well made, yet it features a battery compartment lid (probably case from another meter) revealing bare contacts (you can also see the current shunt), and the lovely live speaker connectors. Also note that when using an european plug there is no earth continuity due to construction of the HOPI’s universal socket.

    It shows current, RMS voltage, frequency (misspelled as frequence), active power, and power factor. Seems to measure quite well. This version is rated 20A, however when drawing more than 10A (water kettles, and so on) the shunt begins to heat noticeably, also the socket is rated 13A. It can also go crazy when dealing with bizarre power factors of 0,05 and less, like with capacitor droppers.


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