Current Measurements

The following tables give you an idea of the average current draw in three different operating modes with the Bluefruit LE UART Friend:

  • Fast Advertising Mode (the first 30 seconds after power up)
  • Slow Advertising Mode (>30s since power up)
  • Connected Mode (using the UART profile in this case)

Test Conditions

The board was powered from a fully charged 1200mAh 4.2V LIPO cell running at 4.2V. Power efficiency will generally increase as the LIPO battery voltage drops, so 4.2V should be considered a worst case scenario.

  • Power Supply: 1200mAh 4.2V LIPO Cell (at 4.2V)
  • Firmware: 0.6.2

Fast Advertising Mode

The first 30 seconds that the Bluefruit LE UART Friend is powered up it will enter 'Fast Advertising Mode', which sends an advertising packet once every 100ms.

  • Average Current: 1.44mA
  • Peak Current: 13.5mA
  • Expected Battery Life: 832 hours (~34.6 days)
The MODE LEDs can be seen blinking in regular intervals as the three rectangular bumps at the bottom of the chart.

Slow Advertising Mode

After 30 seconds the Bluefruit LE UART Friend will enter 'Slow Advertising Mode', which sends an advertising packet once every 546.25ms.

  • Average Current: 1.25mA
  • Peak Current: 13.5mA
  • Expected Battery Life: 956 hours (~40 days)

Connected Mode (UART)

The following measurements illustrate the average current draw in connected mode (with the connected LED enabled).  UART mode was used as a test case.

  • Average Current: 1.86mA
  • Peak Current: 15.2mA
  • Expected Battery Life: 645 hours (~26.8 days)
This guide was first published on May 01, 2015. It was last updated on May 01, 2015. This page (Current Measurements) was last updated on Dec 12, 2019.