NOTE: This guide serves as documentation for the tests that were conducted on the cells, not as the best way to do these tests in the future. The best way to get controlled cell data is to measure cells using an Source Measurement Unit which supports charging and discharging so we can control the amount of rest time in between charge and discharge, as I believe this had a large effect on some of the results. Automated test procedures can also be developed which will greatly reduce testing time.
In order to select the best cells for MSXIV, lots of testing must be completed to properly characterize the cells. We want to use the safest, highest energy cells in order to maximize the capacity of our battery pack. Several new cells have come out since MSXII and are looking promising based on online reviews, so we will be doing a comprehensive test of the best cells on the market.
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- We will be using strips of MSXII’s busbars to connect the cells in the 4P configurations.
- For the single cell initial tests, we will use a removable system - clamping the cells in so we don’t ruin the potential to spot weld cells later (spot welding twice to a cell does not work well, as once the original tab is removed, the top is no longer flat, making it harder to get a good spot weld). This will be done using dimpled copper strips, and some kind of clamping mechanism to hold it in place.
- For the multi-cell tests, we will use extra copper busbars from MSXII and have the mainspot weld 4 cells together using nickel strips soldered to these copper plates.
Measuring Internal Resistance:
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