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Shem Kim

kirstenticzon

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Approach

Pros

Cons

Plate

  • Better for thermal distribution: helps to dissipate heat evenly across the cells

  • Stronger/ more physically reliable: provides more structural support and reduces the stress on connections

  • Easier for us to use / implement ( ? ): When we decide on a design we can machine it in batches ?

  • Lower resistance variation: More consistent electrical connections across the cells

  • Harder to replace individual cells: if one fuse blows, 1. as all cells are connected you cant just removed that one cell alone, 2. you’d probably need to replace the entire plate at that point

  • Design issues:

    • if we’re designing it ourselves there's a lot of space for error, if it isn't made correctly there's possibility for uneven current distribution and some cells would end up with higher loads

  • More material: considering the weight factor, these plates are definitely the heavier option

Wires

  • Easier cell replacement: since each fuse is individually attached. if a fuse blows only that specific wire needs to be replaced

  • More leeway with placement and design: we have more variety in choosing the fuses that are right for our cells compared to a harder search for the exact plate that fits all requirements of our cells

  • Lighter weight: uses much less material

  • Might be cheaper: this approach requires no custom machining, just spot welding we can do ourselves

  • More work to implement: since each fuse is individually attached it will take a lot more attention and time to carry out

  • Inconsistent resistance: subject to small variations in wire thickness or weld quality can create uneven current distribution (more room for human error to matter)

  • Weaker stability: no structural reinforcement like the plate

  • More points of failure: since each wire is kind of doing their own thing they all have their own chances of weakening or breaking over time.

Testing procedure:

  • Plate approach

    • Electrical performance (to ensure fuse plate allows desired current to flow)

      • measure resistance across multiple points on the plate (check uniform distribution)

      • apply increasing current to simulate overcurrent conditions to determine the actual blow current and compare to the design value

    • Thermal behaviour (check how well it dissipates heat)

      • run a continuous discharge cycle and record temperature at different points on the plate

      • or use simulations to model the heat dissipation

    • Stress tests (checking it can withstand vibrations)

    • Failure tests

      • force a single cell failure (overcharge, external short, thermal runaway)

      • if blown fuse disconnects, verify adjacent cells status, (did they experience any electrical or thermal stress as a result of the blown fuse)

  • Wire appraoch

    • Electrical performance

      • measure wire resistence to ensure uniformity across cells

      • slowly increase current to record at what point the wires melt

      • consistently check if some wires heat up more than others (checking for uneven conditions)

    • Thermal behaviour

      • measure temperature in high-current conditions

      • test different wire materials to compare heat dissipation (research for wire materials to be written below)

    • Durability (strength tests)

      • perform vibration testing or use simulation to see if the expected force is enough to break the connections

    • Failure tests

      • force a single cell failure (overcharge, external short, thermal runaway)

      • if blown fuse disconnects, verify adjacent cells status, (did they experience any electrical or thermal stress as a result of the blown fuse)

      • observe any unintended side effects ie thermal damage to nearby components or sparking

Hypothesis prior to testing

Test

Plate

Wire

Implementation

Easier

More time consuming

Electrical uniformity

more consistent across cells

variability in individual wires

thermal dissipation

spreads heat more evenly

potential for localized hotspots

repairs

hard to replace individual fuses

easier

vibration resistance

more robust

wires can loosen over time

failure isolation

works if designed properly

works if wire melts fully