Summary Review

The new Seasonic PowerAngel is a small, low-cost, AC power monitor that can be used to help evaluate and troubleshoot various pieces of computer equipment or other home appliances.

A few months ago we introduced you to a line of power supply units manufactured by Sea Sonic Electronics.  Today we have something a little different to show you.  The new Seasonic PowerAngel is a small, low-cost, AC power monitor that can be used to help evaluate and troubleshoot various pieces of computer equipment or other home appliances.  Have you ever wondered how much electricity your PC or monitor consumes or what the true RMS voltage, current, or Power Factor is?  Well, the Seasonic PowerAngel can answer those questions and help identify power-wasting appliances and forecast how much it costs to operate all your PCs 24/7.

Seasonic PowerAngel AC Power Monitor - Cases and Cooling 5 Seasonic PowerAngel AC Power Monitor - Cases and Cooling 6

Seasonic PowerAngel:  $37.99 MSRP USD

Features and Potential Uses

  • Help to forecast and manage your electric bill
  • Monitor AC power quality to help protect sensitive equipment
  • Use to help select correct size Uninterruptable Power Supply (UPS) based on real VA requirements
  • Pocket-size, light weight and stylish design
  • Use it anywhere with 120 VAC appliances

The Seasonic PowerAngel is easy to use thanks to its compact size, easy to read LCD display and clearly labelled function buttons.  There is a three prong plug molded into the backside of the PowerAngel so it can be plugged directly into a wall receptacle or power strip.  The power cord of the device to be measured then plugs into the receptacle on the front panel.

Seasonic PowerAngel Technical Specifications


133.6 x 70.0 x 39.6mm (L x W x H)



Operating Voltage

85~125 VAC 50/60 Hz

Maximum current

15 Amps

Maximum power

1875 VA




ETL for US and Canada


Seasonic PowerAngel AC Power Monitor - Cases and Cooling 7


The Seasonic PowerAngel has eight different modes of operation, which are selected using the function buttons on the front panel.  Three of the buttons have dual functions, which toggle back and forth each time the button is pressed.





RMS Voltage

The actual voltage at the AC outlet


RMS Amperes

The current drawn by the device measured



The power consumed (Active Power or True Power)



The volt-amperes consumed (Apparent Power)



The frequency of the AC voltage


Power Factor

The difference between Active Power and Apparent Power


Kilowatt Hour

Accumulated power consumption over time



Total expired time (built-in timer used to calculate KWH)

The AC voltage and current are both measured as true RMS (Root Mean Square) values.  Multiplying the RMS voltage times the RMS current gives the Apparent Power, which is measured in Volt-Amps (VA).  Because most AC circuits incorporate inductive and capacitive reactance, a Power Factor (PF) is used to calculate the Active power or “True Power” a device is consuming.  The True Power can be found by multiplying the Apparent Power times the Power Factor.

True Power (watts) = Volts (RMS) x Amps (RMS) x Power Factor


I had a good time roaming around my house testing various pieces of computer equipment and several appliances.  As advertised, the PowerAngel was easy enough to use. I found plugging the PowerAngel into a power strip worked best for me so that it was sitting flat on the bench in front of me during use. 

Seasonic PowerAngel AC Power Monitor - Cases and Cooling 8

Seasonic claims the PowerAngel is accurate to within 1% on the RMS voltage and current measurements and within 2% on the calculated power measurements (W and VA).  As a quick check, I compared the AC line voltage as measured by the PowerAngel with my FLUKE 87 III True RMS digital multimeter.  They agreed within 0.5 VAC (~0.4%).  Very good!

  • PowerAngel  119.1 VAC
  • Fluke 87 III   119.6 VAC

The following table compares the readings I recorded for one of my test computers running with the system at idle virsus running under full load.  (Abit NF7-S Rev2, AMD XP-2500M, ATI 9600 XT, 1 GB Mushkin PC2700 RAM). 

CPU Idle

CPU Full Load

119.4 VAC

119.2 VAC

0.76 Amps

0.86 Amps

91 VA

102 VA

88 Watts

98 Watts

59.9 Hz

59.9 Hz

0.97 PF

0.96 PF


Plugging the numbers into the standard power formulas will help illustrate the relationship between the different electrical values. 

Apparent Power = 119.4 V x 0.76 A = 90.7 VA (the PowerAngel reported 91 VA)

True Power = 119.4 V x 0.76 A x 0.97 PF = 87.9 Watts (the PowerAngel reported 88 Watts)


The Seasonic PowerAngel is portable, easy to use, and proved to be quite useful.  I can highly recommend the PowerAngel to anyone who is curious about the electrical parameters and/or power consumption of their PC equipment and other household appliances.  With a MSRP of $37.99 USD, it’s a real gem.  Our thanks to Seasonic for sending us the PowerAngel to review.  Additional information is available on the Seasonic website.