Is this SoH OK?

[MickeySw]

However, any reported SOH will need to be taken with a pinch of salt because, for EV applications, manufacturers build in a hidden "upper" buffer of unusable capacity. Hence any significant degradation in SOH can be mitigated by the EV's BMS software 'releasing' some of that buffer in to general usage so as to reduce the apparent degradation of SOH to the average user. So, without knowledge of the amount of upper buffer that has been deployed, the SOH is somewhat meaningless.

EV manufacturers deliberately underreport the max capacity of a HV battery by a few %, therefore SoH will remain 100% until that ‘buffer’ is ‘used up’.

I agree, a SoH of 100% is somewhat ‘meaningless’, however once you drop below 100%, SoH will become accurate.

Imho the only way for the BMS to release ‘unusable hidden upper buffer’ for ‘general use’ is to increase the cell voltage, has anyone seen evidence of that happening?

 

[Everest]

OK, I didn't mean increase the SOC to which the battery is charged, I meant a release of top buffer to keep the apparent SOH higher. From what I have read about on the Internet (so it must be true!!) some manufacturers, e.g. Tesla and VW for example, have algorithms to make some of that under-reported capacity available. I suspect that would be done over time, rather than all at the beginning - but who knows