I have a device that's being battery powered and I would like to measure the power consumption over a longer period of time (~24Hours). I want to read both the voltage of my battery and the current being drawn by my device. I would need something battery powered that could log the data into a raw .csv like format so I can later run analytics on it.

I know this should be really simple but I'm not exactly sure what to Google to find what I need for this application.

Edit: Hoping not more than ~$500. Looking at 12V-48VDC and current <10A. However I would like fairly high accuracy because my application is very sensitive to power consumption. Rate could be on the order of seconds...maybe even minutes but doesn't need to be miliseconds.

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    \$\begingroup\$ Welcome fullyjosh. What is your budget? You could either buy a current logger with this functionality but could cost 50 - 150 dollars. You could also built something yourself fairly easily (and cheap) with for example an Arduino or Raspberry Pi. \$\endgroup\$ Sep 16, 2019 at 15:51
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    \$\begingroup\$ A lot depends on what voltage and current you want to log, and at what rate. If your device is particularly low power (or spends a lot of time asleep) then measurement is more of a challenge. Try to define your requirements: 1. number of log entries 2. Voltage range. 3. Current range. \$\endgroup\$ Sep 16, 2019 at 15:51
  • \$\begingroup\$ It's going to be hard to make the meter itself battery powered. Consider something like an INA219 on an Arduino or similar to rapidly take and totalize readings giving periodic summary output to a PC or raspberry pi which saves them. \$\endgroup\$ Sep 16, 2019 at 16:59
  • \$\begingroup\$ @ChrisStratton good idea although IMA219 won't allow for the specced 48 VDC unfortunately. \$\endgroup\$
    – jaskij
    Sep 16, 2019 at 23:41
  • \$\begingroup\$ @JanDorniak indeed, but that requirement was only added in an edit long after the comment. Hall sensors might, though the scope of the power requirement in combination with the very low sampling rate requirement raises the question if the installed battery capacity is actually up to the task. \$\endgroup\$ Sep 16, 2019 at 23:43

2 Answers 2


There are few options for such a task:

  1. A DMM with data logging capability. You need two of them, one for current and one for voltage.
  2. A DAQ board, an analog front end to convert the current into voltage and a PC. You will need one with 2 channels and sufficient resolution and for your requirements.
  3. A purpose build device for such task - usually they are called IoT power monitors or something similar. Such a device implements the ADC and analog circuitry, you will need a PC to complete the system.

If you have an Arduino and can tinker it you can try the building ACS712 Current Sensor And Arduino.

  1. For the Arduino you can set-up two channels to measure a) Voltage and b) Current through the ACS712 sensor.

  2. Another way is to just measure current by measuring the voltage through a "sense" resistor but this extra resistance affects the load current by a bit.


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