Page Comparison

Pre-Meeting Notes:

• What is the current state of modules?

  • 9 modules manufactured

    • QA: doing series spotwelds first decreases resistancehot glue thermistors to busbar (only top and bottom as they get hottest)

      • modules were redone to do parallel spotwelds first

  • About thermals

    • Epoxy will increase rigidity of module and won’t have effect on heat transfer as cells are covered on top and bottom anyways

    • About Thermistors

      • Thermistors should be attached with hot glue instead of kapton tape

      • each module can have 3 thermistors

      (

      • , put them on top

      ,

      • of module so it is easier to

      manufacture)

      • make?

      • busbars are good conductors, MS14 had thermistors only on busbars. Busbars are better for catching any cell that heats up

      • we should put 1 on each busbar and 1 on center cell on negative end (closer to jelly roll)

  • About Voltage taps

    • NOTE there will be a difference b/w sum of voltage taps and pack voltage (through multimeter) because of Vdrop from busbars Vtap position

    • Donna asked about Vtap positions on bottom of module, Micah says they are ok (placement is closer to some cells, but prob only ~1mv diff)voltage drop may occur between voltage taps (resistance of busbar)dif

  • 1 tested w/ forest

    • quick test access to HV room w/ big eload (chroma?)(not following testing plan)

    • future tests to use HV testing room’s Chroma

• What do we need to do W24?

  • 9 modules + 5 spare modules manufactured and tested/validatedTest 8 modules

  • 3 aux batteries

    • Testing: basic capacity test (full cycle + IR)

• Review Module Testing Plan with Micah

  • About IR Test

    • All modules should be at same SOC when testing IR

    • cannot use multimeter because

    of method

    • multimeters measure resistance by sending current through the resistance (doesn’t work for battery)

  • About Balance Test

    • wouldn’t do balance test

  • About Full Discharge Test

    do

    • High current testing is most important

  • when making tests, what can we do if it doesn’t pass?

  • wouldn’t do balance test

  • • Do full discharge for max current test

    • when checking temperature, use temperature rise from ambient rather than absolute temperature

    first

  • Extra test: look at voltage of each individual cell

  • When making tests, what can we do if it doesn’t pass?

  • Pack testing

    • First pack test should be as controlled as possible (chroma e-load)

  • Extra test: look at voltage of each individual cell

  • Ideal pack testing

    • take bench outside with pack and array, discharge and watch array charge the pack

    • OR put the whole system together, see vehicle move, watch array charge

  Review Modules with Micah

  • Does he have any concerns with any choices we made?