2013 MS 85 upgrade to MCU2 then HV battery problem

[wk057]

Some data to go with my note above. (Please excuse the crudity of this model. I didn't have time to build it to scale or paint it.)

This is data from one of 057's customer vehicles in the extended service plan program (shared with permission). A very early 2013 S. This is data from a couple of weeks ago. Our monitoring device, using the data above along with other data used internally on the device, determined that the car was going to eventually throw some errors related to an SoC imbalance. The customer was notified, and they were actually already in the middle of a small road trip.

"Imbalance? But wk057, that pack looks very well balanced! Only off by 5mV!" Ah yes, the myth of voltage being the end-all-be-all of balancing. NOPE.

Check out the capacity of some of the groups in the front hump. Notice anything? One of these things is not like the other....

Other data suggests this is the "standard" moisture issue with these older packs.

Sure enough, near the end of their trip, the car threw the "Maximum Charge Level Reduced" error, as the SoC imbalance grew beyond the BMS's ability to handle. (Fortunately, all is well and they managed to make it home. The car is en-route to us for a pack replacement.) Letting the car sit for weeks can temporarily resolve some of the presentations of this error by giving the BMS time to catch up with the capacity delta, but with use it will always end up back in a position where it can't keep up and will have to severely limit charge levels and discharge rates.... right up to the point where you can't drive anymore.

To Tesla's credit, in much older firmware you would have just been left stranded instead of the BMS just reducing usable capacity and power.

 

[Rocky_H]

"Imbalance? But wk057, that pack looks very well balanced! Only off by 5mV!" Ah yes, the myth of voltage being the end-all-be-all of balancing. NOPE.

Check out the capacity of some of the groups in the front hump. Notice anything? One of these things is not like the other....

Can you help explain what we are looking for or supposed to be seeing? I've seen something like this posted before, where it's a graphic like this, with a vague note like, "Wow, check THIS out!" and I can't ever figure out what we're supposed to be seeing. It kind of feels like when the detailer was about to put the paint protection coating on my car and was having to take about 5 tries to get me to see the supposed "marks" that were in my paint that seemed invisible to me.

I see some of the voltages highlighted in scary red, but 3.952V doesn't seem very off from 3.951V, which most of the cells are.

And you talked about capacity, but some of the scary marked ones are 216 Ah, which is exactly the same as the not marked ones. One of them does show 211 Ah, which is low, but it's not a highlighted number, so is that not supposed to stand out?

So what's supposed to be jumping out at me?

 

[MP3Mike]

And you talked about capacity, but some of the scary marked ones are 216 Ah, which is exactly the same as the not marked ones. One of them does show 211 Ah, which is low, but it's not a highlighted number, so is that not supposed to stand out?

I don't think anything is "scary marked". The Red background signifies maximum voltage, the green background signifies minimum voltage. And yes that one "brick" being ~5 Ah lower than the rest is likely the problem. (Maybe he should change the background color to red/green for the max/min Ah as well.)

At least that is how I am interpreting the data presented.

 

[wk057]

Can you help explain what we are looking for or supposed to be seeing? I've seen something like this posted before, where it's a graphic like this, with a vague note like, "Wow, check THIS out!" and I can't ever figure out what we're supposed to be seeing. It kind of feels like when the detailer was about to put the paint protection coating on my car and was having to take about 5 tries to get me to see the supposed "marks" that were in my paint that seemed invisible to me.

I see some of the voltages highlighted in scary red, but 3.952V doesn't seem very off from 3.951V, which most of the cells are.

And you talked about capacity, but some of the scary marked ones are 216 Ah, which is exactly the same as the not marked ones. One of them does show 211 Ah, which is low, but it's not a highlighted number, so is that not supposed to stand out?

So what's supposed to be jumping out at me?

It's not super intuitive, but you're correct on the 211 Ah brick (really 210.9, but rounded).

I don't think anything is "scary marked". The Red background signifies maximum voltage, the green background signifies minimum voltage. And yes that one "brick" being ~5 Ah lower than the rest is likely the problem. (Maybe he should change the background color to red/green for the max/min Ah as well.)

At least that is how I am interpreting the data presented.

Correct. And yeah, this interface could use some TLC. The capacity delta is 6.7 Ah between brick 43 and 32... which is pretty high, and signals there's likely a physical issue with the pack. This grew to nearly 8Ah before the car was picked up for shipment to us, and the voltage delta during the customer's trip reached as high as 0.44V at rest (440mV... compared to the 5mV seen here pre-trip).

 

[BStarship]

Hello all,
I have a 2013 MS 85 and recently upgraded to the MCU 2. As soon as I got the upgrade completed I received a call from them saying it’s ready to be picked up but that the charge level is now capped at 52%. Needless to say, I was LIVID. They basically told me that I had an underlying problem with my battery and it is now capped to “preserve” the battery. As you can imagine, this was difficult to take in. They explained that the MCU1 didn’t have the tech to detect the problem in the battery like the MCU2 does and will preserve it. It’s $13k for a new battery out of warranty. The next day it went down another 10%! They said it was an adjustment period to figure out what is safe but recommends a new battery pack.

I honestly don’t know what to believe anymore with Tesla. Love the car but not sure what to do now…anyone else have this problem after MCU2 upgrade? Really crazy to think that I had a perfectly running car one day that would get a full charge, but 4 hours later get charge limit cut in half. willing to explore 3rd party options in Northern CA. Thank you all!

I was talked into a new MCU2 unit also right before the voluntary eMMC chip recall. 6 months out of warranty I received error message and was told remotely, that I needed a new HV Battery and then a couple of days later, after software update, the alert went away. 3 months later out of the blue, I have a capped battery at 111 when I was getting @237ish before, which is average degradation for the car's age. I have a 2013 MS 85 with 88k (free supercharging). Now about 5 months later I have the dreaded limp alerts BMS_u008, BMS_w172, and the regen error code. Tesla SC is again remotely telling me that now I need a new DU (no rear whining). My car has not actually been to the SC as of yet. all of this is remote supposition DX. I loved my car too but after paying it off a few months back, I am ready to cut my losses and get rid of it. With the 3rd parties limited to working on the MCU1 I now am forced to deal with the SC and I really do not trust them either. I need help also finding someone who can assist with real DX or anyway to remove these error codes. I have tried a few suggestions on various threads but nothing has worked so far. I'm sure my car will just die on the freeway one day. Pretty much if Tesla doesn't make adjustments to their pricing and customer service for the average consumer, they are selling cars that will only last 8 years. Expect that after warranty you will need @ 30k to keep your car on the road. I am in Palm Desert, CA (not a cold area) if anyone knows a reputable repair shop that can service MCU2.

 

[Rocky_H]

Pretty much if Tesla doesn't make adjustments to their pricing and customer service for the average consumer, they are selling cars that will only last 8 years.

Well, you're talking about that as if it's a permanent, ongoing state of the company with all of their vehicles forevermore. I don't see it that way. I don't think that's going to be the case with the cars being sold now and in the last couple of years. I think this is more of the problems with the cars Tesla sold in its first couple of years when things were more low volume and custom. They are having troubles with cost effective repair on those. I don't think things are going to be as bad on that with the much higher volume Model 3 and Y, etc.

 

[Droschke]

Hello all,
I have a 2013 MS 85 and recently upgraded to the MCU 2. As soon as I got the upgrade completed I received a call from them saying it’s ready to be picked up but that the charge level is now capped at 52%. Needless to say, I was LIVID. They basically told me that I had an underlying problem with my battery and it is now capped to “preserve” the battery. As you can imagine, this was difficult to take in. They explained that the MCU1 didn’t have the tech to detect the problem in the battery like the MCU2 does and will preserve it. It’s $13k for a new battery out of warranty. The next day it went down another 10%! They said it was an adjustment period to figure out what is safe but recommends a new battery pack.

I honestly don’t know what to believe anymore with Tesla. Love the car but not sure what to do now…anyone else have this problem after MCU2 upgrade? Really crazy to think that I had a perfectly running car one day that would get a full charge, but 4 hours later get charge limit cut in half. willing to explore 3rd party options in Northern CA. Thank you all!

@Espi2451 -

Can it be that they upgraded your software from the older version you had on MCU1 to the latest MCU2 software which might have a better diagnostic capability than your older software?

What software version did you have with MCU1 and what do you have now with MCU2?

 

[wk057]

With the 3rd parties limited to working on the MCU1...

Maybe other third parties...

Long story short, you're probably going to need a battery. The one error could mean an external isolation issue (not sure why they'd jump to the drive unit), but not necessarily if there's a pack issue. If you lost significant range and are seeing BMS errors, then it's very likely a pack issue.

 

[Rqcg]

The 2012 and 2013 S packs are pretty hit or miss these days. Some are rock solid, others have developed terrible moisture ingress issues that lead to damage.

Would getting a refurbished 90 pack to a 2013 85 help with these issues? I’m still on MCU1 and recently has the following issues pop up and be gone again soon after: BMS_u011 Unable to Fast Charge (Solved after plugging in to other stall), BMS_u016 Please wait while system performs check (gone after Park), BMS_w035 Vehicle may not restart (gone after Park) and BMS_f035 Vehicle may not restart (gone after Park also). None of them showed up since but definitely makes me scared.

 

[ddb1001]

Hello all,
I have a 2013 MS 85 and recently upgraded to the MCU 2. As soon as I got the upgrade completed I received a call from them saying it’s ready to be picked up but that the charge level is now capped at 52%. Needless to say, I was LIVID. They basically told me that I had an underlying problem with my battery and it is now capped to “preserve” the battery. As you can imagine, this was difficult to take in. They explained that the MCU1 didn’t have the tech to detect the problem in the battery like the MCU2 does and will preserve it. It’s $13k for a new battery out of warranty. The next day it went down another 10%! They said it was an adjustment period to figure out what is safe but recommends a new battery pack.

I honestly don’t know what to believe anymore with Tesla. Love the car but not sure what to do now…anyone else have this problem after MCU2 upgrade? Really crazy to think that I had a perfectly running car one day that would get a full charge, but 4 hours later get charge limit cut in half. willing to explore 3rd party options in Northern CA. Thank you all!

I upgraded to MCU2 about 2 months ago. My battery got capped right after the OTA update.
There are a lot of people that got capped right after an OTA update.
Maybe they updated your software when they upgraded the MCU?

 

[wk057]

There's nothing in the OTA updates specifically to trigger issues with the batteries.

However, any OTA update does a reset of the battery as part of the update process. Generally the BMS is online 24/7 without resets, except for during/after an update. This can get the BMS to start it's evaluations of some things over again and cause it to detect certain issues more quickly than it would otherwise. The issues are still real and still there and will still trigger alerts at some point anyway.

In short, it's not the OTA that caused a problem. The problem with the pack was already there before the OTA.

 

[wk057]

There's nothing in the OTA updates specifically to trigger issues with the batteries.

However, any OTA update does a reset of the battery as part of the update process. Generally the BMS is online 24/7 without resets, except for during/after an update. This can get the BMS to start it's evaluations of some things over again and cause it to detect certain issues more quickly than it would otherwise. The issues are still real and still there and will still trigger alerts at some point anyway.

In short, it's not the OTA that caused a problem. The problem with the pack was already there before the OTA.

A note I meant to put here also, MCU1 and MCU2 share the same BMS firmware, so nothing different there either. Upgrading to MCU2 doesn't do anything to the battery.

 

[Espi2451]

Thanks for your response!

 

[Droschke]

A note I meant to put here also, MCU1 and MCU2 share the same BMS firmware, so nothing different there either. Upgrading to MCU2 doesn't do anything to the battery.

My understanding is that when Tesla decides to update the BMS firmware, they always include that update in a regular OTA software. Is that correct or are there other ways they update the BMS software?

 

[Espi2451]

UPDATE:

I decided to just bite the bullet and go for a reman 90kw battery. They installed it a couple days ago and called today saying it was ready and that they actually put in a new HV battery rather than reman. SC said they will adjust the price from 17K down to the original estimate which was 13k. I guess that’s always a plus that it’s a new battery and for original quoted price. At 100% charge it looks like I get about 295 miles. Seems on par. I’ll pick up in a couple days. They gave me a loaner 22’ MY from Hertz which was cool of them to do at no cost to me. I’ll provide updates once I get it on my hands. I’ve been monitoring over the app and have been noticing some vampire drain, a little more than I’d hope but not sure if this is normal for a newly installed HV battery. Thanks all!

 

[Droschke]

UPDATE:

I decided to just bite the bullet and go for a reman 90kw battery. They installed it a couple days ago and called today saying it was ready and that they actually put in a new HV battery rather than reman. SC said they will adjust the price from 17K down to the original estimate which was 13k. I guess that’s always a plus that it’s a new battery and for original quoted price. At 100% charge it looks like I get about 295 miles. Seems on par ...

Are you sure they have installed a "new" 90kWh pack (probably a 1014116-00-C) and are only charging you only $13K for it?

Would be interesting to see your invoice.

 

[Espi2451]

Are you sure they have installed a "new" 90kWh pack (probably a 1014116-00-C) and are only charging you only $13K for it?

Would be interesting to see your invoice.

Well he said the regional manager has to sign off on it next week to approve the price adjustment of the new battery. I guess their mistake..? Regardless, I’m paying 13k either way. I’ll take a closer look at the final invoice.

 

[aerodyne]

Sounds like horse manure to me…

Agreed. MCU has nothing to do with BMS data, which can be seen with any CAN bus reader and app like SMT.

I think SvC broke your car frankly.

 

[Espi2451]

Agreed. MCU has nothing to do with BMS data, which can be seen with any CAN bus reader and app like SMT.

I think SvC broke your car frankly.

Are you sure they have installed a "new" 90kWh pack (probably a 1014116-00-C) and are only charging you only $13K for it?

Would be interesting to see your invoice.

 

[Espi2451]

Is this the better battery? The “C” version?