Problem-statement:
For MSXV, more than 50% of manufactured modules had a dead-cell, decreasing overall pack-capacity
Possible reasons:
Manufacturing issue - if a 4.2V and 2.5V battery were placed in-series, could it kill the battery?
Testing issue - were defective cells placed in the modules (i.e., did our testing fail to catch them)?
Spot-welding - may have damaged some cells
Next-Steps:
Research other-methods for how could a battery could drain that-quickly
Vibrations - look into 1. designing the modules to reduce vibrations (padding etc.) and 2. making sure the next-design of the enclosure is as-tight as possible to fit the modules
Verify Micah’s test program
Other things to think about:
Vibrations - dead cells were found after manufacturing, not while modules were in the car - vibrations kill the battery pack - severe vibrations can cause the internal components of the battery to become damaged - if we are doing testing in the field this is a cause of concern