For nEDM we would like to operate the batteries in a mode where they discharge (supply load current) for 1000 seconds, and charge for about 1200 seconds. To simulate this with batteries we have on hand, we propose the following:


This is a 12V 2.3Ah battery. The data sheet a charge procedure:

  Cycle Applications: Limit initial current to 690mA. Charge until battery voltage
  (under charge) reaches 14.4 to 14.7 volts at 68°F (20°C). Hold at 14.4 to 14.7
  volts until current drops to under 23mA. Battery is fully charged under these
  conditions, and charger should be disconnected or switched to “float” voltage.

Proposed test:

  • Connect battery to bench supply with current limit set to 690mA through series sense resistor
  • Connect supply to AC through solid-state relay
  • Connect load (24 ohm 10W power resistor) to battery through relay
  • Attach a linear temperature sensor to the battery
  • Connect computer DAQ board:
    • Digital outputs to control relays (2)
    • Analog inputs to measure charge current and battery voltage
    • Analog input to measure battery temperature

Write test software to charge battery to 1200 seconds, then discharge for 1000 seconds in a cycle, monitoring all analog quantities periodically (every 10s?)


link to current software

Last modified 10 years ago Last modified on Nov 8, 2013, 10:17:54 AM