Hacky wrote: ↑Thu Jan 13, 2022 1:36 am
Dispite many other statements, the i3 does not hold back a buffer at the higher end of the cell voltage range. The buffer only prevents exhaustive discharge.
You are basing your assertion on the output of the Electrified app that indicates a battery pack voltage of 402 V, and then you assume that this is the maximum possible voltage for a pack of 96 120 Ah cells. Pack voltage is temperature-dependent, so did you correct this voltage for the cell temperature?
In one of the screen shots in the forum that you referenced, the Electrified app displays a battery health of 99%. It also displays a charge level range from 12.0% to 96.3%. You state that no high charge level unusable buffer exists yet the Electrified app shows a 3.7% buffer. The fact that you believe the pack voltage but not the maximum allowed charge level of 96.3% reduces the credibility of your assertion.
Electric Vehicles and the BMW i3 (60, 94, & 120 Ah)
by David Bricknell includes charts from testing labs that clearly show low and high charge level unusable buffers. His description of the battery management system clearly states that unusable buffers exist at both low and high charge levels. The difference between BMW's published gross and net battery pack capacity can't be explained by the existence of only a low charge level unusable buffer unless one assumes an unreasonably large low charge level unusable buffer. BMW's TIS Website describes the SME as controlling the charge level range of the battery pack without specifying buffer sizes which vary by battery cell capacity.
There's overwhelming evidence from credible sources disputing your assertion that no high charge level unusable buffer exists.
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