2021 M3LR Battery Replaced Recently (Experience)
Got the dreadful **BMS\_a079** warning on my 2021 Model 3 Long Range at 108k miles. I charge to 80% on the daily and charge to 90% for longer commutes once a week. During lunch, I got the Unable to charge - Maximum charge level reached (BMS\_a079). If you get this error, schedule the service appointment right away. Although my appointment was 10 days out, I ended up taking the car in the next business day. It will tell you you can continue to drive and charge up to 50% but that is not true. I drove it the next day and got it to about 44% and tried to charge at home. It would not charge. Then I started getting the **BMS\_a074** (Maximum battery charge level reduced) error every minute. Once I took the car into the service center, they already had the HV battery on order since I had booked the service appointment 3 days prior. They pretty much know if they see that BMS\_a079, it will require a HV replacement. Service advisor say they keep some battery packs on hand but also have local warehouse that stocks them. I dropped my car off Monday morning. The HV battery replacement completed Wednesday afternoon. I did have to request a loaner. Be persistent if they say they do not have any on hand and it depends on eligibility. If the repair is under warranty and it is an extended/long repair, service center should provide you a loaner. I looked at the repair invoice and it was indeed the REMAN battery (1137375-GC-W). Based on research on the reddit and tesla forums, they try to match an equivalent degradation battery. In my case it seemed pretty close. At 80% before the battery failure I was at 231 miles range and now with the REMAN battery I'm at 234 miles at 80% charge. I still haven't charged to 100% yet on the REMAN but previously on the OG battery I was around 291 miles at 100%. Since it was replaced under warranty, the REMAN battery is only covered until the remaining of the original 8yr/120k battery warranty. I'm wondering if I should get the 24month/30k battery warranty extension for $2000 as I approach the 120k. I read posts that the REMAN batteries do not last as long as OG batteries. Trying to see what others have experienced when it comes to longevity on the REMAN batteries.