Page Comparison

[DRAFT]

Objective:

• To choose a module prototype to move forward with. [NOT PRODUCTION LEVEL TESTING]

  • Thermal Performance: Is the module easy to cool? Are there risks of a thermal runaway?

  • Electrical Performance: Does the module work? Are there areas with extremely high current density? IR?

Context:

• put our packs/modules/cells through <100 cycles

• “The major effects (sudden capacity loss) are most likely to appear after 100 cycles of the pack, however, minor effects will always be present” [2]

• our pack will be assembled for 1-2 months

Background Information:

OEM Specs:

It is important to inform our test procedure from the OEM specs for the cells we are planning to use:

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The module will be subjected to varying cycling patterns in various environmental condiyions. It should be easy to cool and safe from thermal runaway, melting, shorts, etc.

Procedure:

Software Setup (Skip)

1. Install (follow their respective instructions closely)

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1. Storage Charge + Inspection

   1. Storage Charge to maintain cell safety

      1. 33.6V max voltage (~4.2V/cell)

      2. 5.8A CC portion

      3. 25A end Current

         1. We don’t want the storage to take a ton of time - we don’t need to wait for the current to drop all the way - voltage will sag a bit after finishing the charge, but we have increased the voltage to 3.8V/cell instead of the standard 3.7V/cell to account for this.

   2. After the above procedure is followed, we will calculate the capacity of each of the parallel groups to ensure there are no major discrepancies. Any voltage limits that were exceeded or not hit correctly, we will be able to create a model of the LG M50 cells and use that to extrapolate the data to get a full-capacity measurement. We will also examine the temperature graphs and the IC/DV graphs to ensure the uniformity of the cells.

References:

[1] The Fundamentals of Battery/Module Pack Test (nhresearch.com)

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