Hi Everyone!
I myself am guilty of the old battery degradation panic attack! Please don't worry, if you're suffering from something similar... I have a super simple and easy fix for you!!
I'm calling it a slightly enhance version of what you've probably already read... but with a modified procedure.
Common recommendation is to lower soc to below 10% and then charge to 100%... and allow to balance cells, and hopefully recalibrate the BMS. For me, this didn't work.
I did the above... reluctantly though, as we're not recommended to go super low on charge or super high. After doing that procedure, I actually saw a loss in range... and then really went down the rabbit hole frome there.
What I've come to find out... is I was following Teslas recommendationa to a T. I mean if you get home with less than 10% Tesla gives a warning you're risking permanent damage to the battery if you don't plug it in right away! So, after taking some time to reflect on my charging habits, I realized my car was either moving, or plugged in.
The issue with that, is that the BMS only ever gets one reading. Mine was always 90%... and then more recently 80% per Tesla recommendation... which only made me see the estimated miles moving lower and lower.
I was feeling super discouraged... and super pissed.... especially because I had to repurchase in Sept of 22 at maximum price due to my wife totalling my first one in April of 22. I hadn't had the same issue with my first car... and paid less with nearly half the apr in Sept of 21 on the first car.
I left it be for while... still seeing my miles decrease little by little. When I got to 221 at 80% SOC... then 218-219. I was determined to figure out what was really going on.
I started digging again, and this time I found a link in the comments of someone else's thread. Can't find it again for anything in the world. However, the info that link provided was incredible, and helped me discover what was actually wrong with my 22 M3P!!
Let me explain a bit more(I'm sorry for the book). As mentioned earlier, I had followed Tesla recommendations... always plugging in. I work for myself... So I never park anywhere for any amount of time. What this means is that the ONLY reading my cars BMS has ever gotten is at 90% SOC... followed by 80% SOC.
The car needs 3 hours minimum to take a reading!!! This is the key to the whole issue. You're not at the grocery store for 3 hours and even if you are... if sentry mode is on... your car isn't asleep!! It needs to be in deep sleep (simplified terms) to get a reading. It needs multiple readings at different states of charge to get a good estimate on true capacity!!!
I've only been following the steps for a not even a week. I was down to 70kwh according to energy screen calculations before starting my new charging routine. Showing 218-219 at 80% SOC. I'm already back up to 228 at 80% SOC and seeing a little over 73kwh using energy screen calculations!!!! It's 50° fahrenheit here too. I can only imagine warmer weather would show a bit more!!
My car is always charged at home via a 2 wall connector setup. So it's more less trickle charging at 24 amps. Ive only charge to 100% once... and drove off immediately... before it even had time to balance as I was paranoid of letting it sit at a high soc!! Lol!
It's very possible I could still have a cell imbalance that will need to be corrected at some point as well. But I'm purposely avoiding that for now... to see what BMS recalibration alone can do.
So for now, I'm simply getting different SOC readings.. 30 couple percent. 40 couple percent. Wherever it is when I get home... I leave it unplugged... set an alarm so I don't forget to go and plug it in for next day. But badda bing badda boom!!! I'm getting miles back instead to lose for first time since owning it!!!
Really hoping this will help someone else who's seeing the same!!
Keys points are
** Iffffff you are never parking anywhere other than home for longer than 3 hours with sentry mode off...
** Your BMS is only ever seeing set limit SOC vs varying percentages.
** Fix this by leaving car unplugged for 3 hours minimum when returning home prior to plugging in... at as many different SOC's as possible.
** Be sure your sentry mode is either off, or set to not work at home in the safety menu... as the whole reason for leaving it sit unplugged is to go into deep sleep... which is need for the BMS to get its readings!
*No need to drain battery to super low numbers.
*No need to charge to super high numbers.
*Within a week of the above... you should already see the miles start to climb!!
I myself am guilty of the old battery degradation panic attack! Please don't worry, if you're suffering from something similar... I have a super simple and easy fix for you!!
I'm calling it a slightly enhance version of what you've probably already read... but with a modified procedure.
Common recommendation is to lower soc to below 10% and then charge to 100%... and allow to balance cells, and hopefully recalibrate the BMS. For me, this didn't work.
I did the above... reluctantly though, as we're not recommended to go super low on charge or super high. After doing that procedure, I actually saw a loss in range... and then really went down the rabbit hole frome there.
What I've come to find out... is I was following Teslas recommendationa to a T. I mean if you get home with less than 10% Tesla gives a warning you're risking permanent damage to the battery if you don't plug it in right away! So, after taking some time to reflect on my charging habits, I realized my car was either moving, or plugged in.
The issue with that, is that the BMS only ever gets one reading. Mine was always 90%... and then more recently 80% per Tesla recommendation... which only made me see the estimated miles moving lower and lower.
I was feeling super discouraged... and super pissed.... especially because I had to repurchase in Sept of 22 at maximum price due to my wife totalling my first one in April of 22. I hadn't had the same issue with my first car... and paid less with nearly half the apr in Sept of 21 on the first car.
I left it be for while... still seeing my miles decrease little by little. When I got to 221 at 80% SOC... then 218-219. I was determined to figure out what was really going on.
I started digging again, and this time I found a link in the comments of someone else's thread. Can't find it again for anything in the world. However, the info that link provided was incredible, and helped me discover what was actually wrong with my 22 M3P!!
Let me explain a bit more(I'm sorry for the book). As mentioned earlier, I had followed Tesla recommendations... always plugging in. I work for myself... So I never park anywhere for any amount of time. What this means is that the ONLY reading my cars BMS has ever gotten is at 90% SOC... followed by 80% SOC.
The car needs 3 hours minimum to take a reading!!! This is the key to the whole issue. You're not at the grocery store for 3 hours and even if you are... if sentry mode is on... your car isn't asleep!! It needs to be in deep sleep (simplified terms) to get a reading. It needs multiple readings at different states of charge to get a good estimate on true capacity!!!
I've only been following the steps for a not even a week. I was down to 70kwh according to energy screen calculations before starting my new charging routine. Showing 218-219 at 80% SOC. I'm already back up to 228 at 80% SOC and seeing a little over 73kwh using energy screen calculations!!!! It's 50° fahrenheit here too. I can only imagine warmer weather would show a bit more!!
My car is always charged at home via a 2 wall connector setup. So it's more less trickle charging at 24 amps. Ive only charge to 100% once... and drove off immediately... before it even had time to balance as I was paranoid of letting it sit at a high soc!! Lol!
It's very possible I could still have a cell imbalance that will need to be corrected at some point as well. But I'm purposely avoiding that for now... to see what BMS recalibration alone can do.
So for now, I'm simply getting different SOC readings.. 30 couple percent. 40 couple percent. Wherever it is when I get home... I leave it unplugged... set an alarm so I don't forget to go and plug it in for next day. But badda bing badda boom!!! I'm getting miles back instead to lose for first time since owning it!!!
Really hoping this will help someone else who's seeing the same!!
Keys points are
** Iffffff you are never parking anywhere other than home for longer than 3 hours with sentry mode off...
** Your BMS is only ever seeing set limit SOC vs varying percentages.
** Fix this by leaving car unplugged for 3 hours minimum when returning home prior to plugging in... at as many different SOC's as possible.
** Be sure your sentry mode is either off, or set to not work at home in the safety menu... as the whole reason for leaving it sit unplugged is to go into deep sleep... which is need for the BMS to get its readings!
*No need to drain battery to super low numbers.
*No need to charge to super high numbers.
*Within a week of the above... you should already see the miles start to climb!!
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. Hopefully someone who knows the answer can chime in to help!! 
