That does imply that differential ageing is occurring across the DC cap bank. Could be heat, could be differing electrical loading depending on location on the board. Worth tracking to get more data.
If they are individual caps, I'd recommend measuring them all when you remove them from the HV PCB and noting their location on the PCB as you remove them. It's possible that the design of the PCB is preferentially ageing the ones "nearest" the bus electrically as they get worked harder.
Always...
No worries my friend, happy to help!
Insider knowledge, we used to run bus caps to the thermal limit back in 2009, we literally had them all fitted with thermocouples externally and had a core temp model running real time too, that way you could push everything to the max without killing them...
Don't get me started on these feck stupid rules and changing them mid-season. I wrote the original report and recommendations for this ruleset with a colleague back in 2018 and then watched them get gutted and distorted by both the FIA AND the teams over the interceding years.
It's a mess...
Yep I understand how inverters work, that's the day job! 😉
So basically either designed too small too small to start with (betting it's the same size across all the model variants despite increasing current) and no margin for error and then degrades with heat/voltage stress through use so...
Wait til your AC charger needs replaced as it won't charge your car on a ski trip, your failed fans leave you in Turtle mode in the middle of France, your DCDC converter orange rings every time you use a 400V charger and then 5 out of 7 stepper motors in the HVAC fail.
oh and then the navi...