Daily Archives: June 10, 2015

Power Bank Capacity Tests

YZXredI’m starting a project to test the capacity of a number of power banks, using the YZXstudio Power Monitors supplied by Franky Tong.

I’ll measure the charge (in mAh) required to fully charge the pack and the total charge recovered from the pack during discharge.

The test conditions are as follows:

  • Charge supply device:
  • Discharge device: Asus/Google Nexus 7 tablet (draws about 420mA)
  • Charge monitor: YZXstudio USB3.0 Power Monitor (yellow)
  • Discharge monitor: YZXstudio USB3.0 Power Monitor (red)


Avantek 20,000mAh External Battery Pack

  • Supplied input charge – 19,338mAh (previously 20,185)
  • Recovered output charge (5V) – 13,176mAh
  • Efficiency of boost electronics – 92%

EC Technology 22,400mAh Power Bank

  • Supplied input charge – 21,467mAh (previously 21,265)
  • Recovered output charge (5V) – 13,935mAh
  • Efficiency of boost electronics – 88%

PowerAdd Pilot X7 20,000mAh Power Bank

  • Supplied input charge – 20,092mAh (previously 19,964)
  • Recovered output charge (5V) – 12,588mAh
  • Efficiency of boost electronics – 85%

RavPower RP-PB19 15,000mAh Power Bank

  • Supplied input charge – 11,741mAh

Julian’s Postbag: #42 – USB 3.0 Power Monitors (Red/Yellow)

Two fascinating USB 3.0 power monitors which have super accurate voltage, current and power measurement and some really neat additional features.

USB 3.0 Power Monitor – YZXstudio Voltage Current Meter OLED Charger Doctor #YZXstudio http://www.ebay.com/itm/USB-3-0-Power-Monitor-YZXstudio-Voltage-Current-Meter-OLED-Charger-Doctor-/171657443908

USB 3.0 Power Monitor (Red) YZXstudio Voltage Current Meter High Resolution OLED http://www.ebay.com/itm/USB-3-0-Power-Monitor-YZXstudio-Voltage-Current-Meter-High-Resolution-OLED-/171606912751

Disclosure: These items were supplied to me at no cost for the purpose of making a review video.