Electronics and Software
Engineering Innovation

BMeasure-125i - Scientific Measurements

Battery Testing

One application for the BMeasure-125i was in the research of long life radio sensor batteries in hight temperature applications. The Lorawan radio sensors needed to operate over 30 years at temperatures up to 80 °C. Poly‐carbonmonofluoride lithium cells were considered for this application due to their low self leakage at high temperatures and stable characteristics.

One problem with this type of cell is its voltage drop under high current pulses. With a low power Lorawan sensor there can be TX currents of 24 mA for up to a second. Research was conducted to see how these cells performed with varying duty cycles and current pulses at different temperatures.

A BMeasure-125i was used to perform the measurement and heater control work. Some of the aspects of this were:

  • 3 battery cells were tested at a time
  • The BMeasure's digital IO D0 was used to control the heater in an insulated box where the batteries under test were situated.
  • A temperature sensor was connected to the AI0 input to measure the battery cells temperature. This was used to manage the heater and logged with the data.
  • The BMeasure's analogue output AO0 channel was used to control the battery current through each of the 3 cells under test.
  • The voltage and current through three independent cells was measured using analogue input channels 1 through 6.
  • The voltage and current channels were sampled at 1 ksps and the resulting data stored
  • A simple Python program control the test. This managed the heater, set the battery currents with a programmed cycle and stored the resulting data into a CSV file for later analysis.