... that was issued last year to correct DC charging problems that had triggered dozens of complaints on numerous forums. I think most owners would have had this one by now, unless you avoid going to dealers. I missed it last year at my annual visit by about a week. I have to get a govt-required annual safety inspection and I use the dealer because I know they won't notice (or care about) my technically-illegal aftermarket LED headlight bulbs.
I was awake enough this time around to grab some screen shots of BMS data before and after the update so I could compare them. I wanted to confirm that all cumulative data is reset to zero, which turns out is true, and that includes the 'hours' meter and AC / DC charge counters. No doubt the SoH is included but I can't tell as it was already 100%. It's a shame to lose all that history but that's often the reality with firmware. The BMS by the way is uniquely located inside the battery pack, my pack being replaced Oct 2022 due the well-known recall. I worked out that the pack used was at about 8% SoC when it was installed, not ideal.
During the update process the BMS cannot engage support from the traction battery so it relies on the 12V battery power for the duration. I specifically requested on the job sheet that they 'support the 12V battery' even though I know the procedure recommends it. The reason I raised that was because one owner on FB recently reported that the dealer 'bricked' their car due to missing this crucial detail and had to order a new BMS causing weeks of downtime.
Below are the main relevant changes underlined, mainly the four coulomb and energy counters that act like electricity meters for the battery for current in both directions. Also the hours and firmware revision, readouts unique to the Car Scanner app for some reason.
There's one advantage to having this info zero'ed out just like it was at the factory. If you know the SoC(BMS) when the counters were zero, each time in the future when the SoC(BMS) passes through that same value, the ratio of CED over CEC (cumulative energy discharged v.s. cumulative energy charged) closely represents the battery cycle efficiency.
So, that tells you how much of the energy added by charging can be recovered for use. The last time I estimated this efficiency it was 98%, pretty much at the higher end of what should be expected. I used the moment when CCC = CDC which is close but might be subject to eventual drift due to accumulated errors.
Now that I know the SoC(BMS) at the moment these numbers are useful, I can get more accurate estimations, but only once I've accumulated about another 10,000 km.
![Image]()
My previous estimate of battery cycle efficiency based on the moment when CCC crosses CDC, in practice an event that happens for just several seconds while driving.
![Image]()
I was awake enough this time around to grab some screen shots of BMS data before and after the update so I could compare them. I wanted to confirm that all cumulative data is reset to zero, which turns out is true, and that includes the 'hours' meter and AC / DC charge counters. No doubt the SoH is included but I can't tell as it was already 100%. It's a shame to lose all that history but that's often the reality with firmware. The BMS by the way is uniquely located inside the battery pack, my pack being replaced Oct 2022 due the well-known recall. I worked out that the pack used was at about 8% SoC when it was installed, not ideal.
During the update process the BMS cannot engage support from the traction battery so it relies on the 12V battery power for the duration. I specifically requested on the job sheet that they 'support the 12V battery' even though I know the procedure recommends it. The reason I raised that was because one owner on FB recently reported that the dealer 'bricked' their car due to missing this crucial detail and had to order a new BMS causing weeks of downtime.
Below are the main relevant changes underlined, mainly the four coulomb and energy counters that act like electricity meters for the battery for current in both directions. Also the hours and firmware revision, readouts unique to the Car Scanner app for some reason.
There's one advantage to having this info zero'ed out just like it was at the factory. If you know the SoC(BMS) when the counters were zero, each time in the future when the SoC(BMS) passes through that same value, the ratio of CED over CEC (cumulative energy discharged v.s. cumulative energy charged) closely represents the battery cycle efficiency.
So, that tells you how much of the energy added by charging can be recovered for use. The last time I estimated this efficiency it was 98%, pretty much at the higher end of what should be expected. I used the moment when CCC = CDC which is close but might be subject to eventual drift due to accumulated errors.
Now that I know the SoC(BMS) at the moment these numbers are useful, I can get more accurate estimations, but only once I've accumulated about another 10,000 km.
My previous estimate of battery cycle efficiency based on the moment when CCC crosses CDC, in practice an event that happens for just several seconds while driving.
