Which battery packs have stood the test of time?

[wasdwasd]

Hi,

I'm in the market for a used Model S and am particularly keen to find one with free supercharging. This means that I am looking mostly at 2016-2017 models.

I am m struggling to decide which configuration (in terms of battery size, dual vs single motor) is most desirable. My main concern is with long-term reliability and cost of maintenance.

Obviously a 90D commands a premium over the rest of the range, but reading online and on this forum I get the idea that these batteries specifically seem to degrade more than the others. Should I avoid these?

I'm very interested to know if there has there been any particular battery pack (in terms of size, year of manufacture) that has stood out from the rest in terms of reliability? Conversely, has there been any particular battery that has shown over time to be especially unreliable?

Also, can one expect any significant difference in reliability between AWD and RWD models? Logically you could make an argument either way - RWD has only a single motor, so maybe it gets strained and breaks earlier, but on the other hand AWDs have one more motor that could go wrong and break down. Has the community noted any long-term reliability trends with regards to RWD vs AWD?

Any help or info would be appreciated

Many thanks

 

[DerbyDave]

As far as AWD or RWD, I think if either motor dies, the car is dead. Obviously RWD has only the one motor to go bad.

 

[vcor]

Motors have been very reliable, with a few rare failures. Not sure I'd worry about the motors. The early battery packs (2012-2014) have had some issues over time and were improved in 2014. Pack longevity may have more to do with the environment they have been in than age, but that's not entirely clear. For example, high-humidity and/or salted roads are not great for any car (ICE or EV). Further small improvements have been made over the years, so newer is better.

 

[ucmndd]

Motors have been very reliable, with a few rare failures. Not sure I'd worry about the motors.

The large rear drive unit (which all RWD cars use) has a significant design flaw that results in coolant intrusion into the inverter/electronics housing, corroding and frying the entire motor. It’s relatively common, definitely not “rare”.

The small drive unit, which is used in both the front and rear of non-performance “D” cars, does not have the same design flaw and has proven to be quite reliable. If out of warranty longevity is a primary concern, I would skip the RWD.

 

[EstebanP212]

The large rear drive unit (which all RWD cars use) has a significant design flaw that results in coolant intrusion into the inverter/electronics housing, corroding and frying the entire motor. It’s relatively common, definitely not “rare”.

The small drive unit, which is used in both the front and rear of non-performance “D” cars, does not have the same design flaw and has proven to be quite reliable. If out of warranty longevity is a primary concern, I would skip the RWD.

Isn’t it also true if one of the motors goes car should drive I’ve heard before

 

[wasdwasd]

The large rear drive unit (which all RWD cars use) has a significant design flaw that results in coolant intrusion into the inverter/electronics housing, corroding and frying the entire motor. It’s relatively common, definitely not “rare”.

The small drive unit, which is used in both the front and rear of non-performance “D” cars, does not have the same design flaw and has proven to be quite reliable. If out of warranty longevity is a primary concern, I would skip the RWD.

This is excellent information and exactly the kind of insight I was hoping to get from this thread. Thanks very much

What about the battery packs? Are there any battery configurations to avoid due to reliability problems?

Right now I have my eye on a march 2017 60d that I was planning on upgrading to a 75d. It has less than 30k miles. Is there anything I need to be wary of when buying this model?

 

[wasdwasd]

Motors have been very reliable, with a few rare failures. Not sure I'd worry about the motors. The early battery packs (2012-2014) have had some issues over time and were improved in 2014. Pack longevity may have more to do with the environment they have been in than age, but that's not entirely clear. For example, high-humidity and/or salted roads are not great for any car (ICE or EV). Further small improvements have been made over the years, so newer is better.

Thanks very much for the info

Were there any particularly big jumps in battery tech over the years 2015-2018? Do they all use the same battery chemistry or was it refreshed/updated at some stage over those years?

 

[Krash]

…Right now I have my eye on a march 2017 60d that I was planning on upgrading to a 75d…

The only drawback seems to be range. I think the 75kWh and 100kWh are pretty reliable.

There are rumors that the software locked packs won’t last as long because they never balance (because they never max charge). I don’t think they have been substantiated.

 

[JimmyB]

This is excellent information and exactly the kind of insight I was hoping to get from this thread. Thanks very much

What about the battery packs? Are there any battery configurations to avoid due to reliability problems?

Right now I have my eye on a march 2017 60d that I was planning on upgrading to a 75d. It has less than 30k miles. Is there anything I need to be wary of when buying this model?

You mention above that you're keen to find one with FUSC - in which case, be very careful with a March 2017 60D. I won't rehash what's already been written in a bajillion other threads, but do some thorough reading up on order and delivery dates, SC01 vs SC05 codes etc, as well as being clear on the ownership history of the car.

My 2p-worth would be to find yourself one of the last 'nosecone' 85Ds, and upgrade it to MCU2. I'm biased of course - this is what I had before my current LR+. The battery was rock solid, with only around 1% degradation after 90,000 miles. The AP1 was in many ways better than the "FSD" I have now. The supercharging will be a bit slow, even compared with a 90 pack, but that part of the cost vs range vs charging speed tradeoff when you want FUSC.

The "unicorn" of the FUSC cars would be a P100D with AP2 hardware, but they can be both rare and pricey.

 

[Unclepaul]

100kWh battery seems to have the best reputation in S/X

 

[Russell]

The large rear drive unit (which all RWD cars use) has a significant design flaw that results in coolant intrusion into the inverter/electronics housing, corroding and frying the entire motor. It’s relatively common, definitely not “rare”.

The small drive unit, which is used in both the front and rear of non-performance “D” cars, does not have the same design flaw and has proven to be quite reliable. If out of warranty longevity is a primary concern, I would skip the RWD.

Are you sure all RWD cars have the large rear drive motor? I thought it was just the Performance cars that had it, 2wd & 4wd. My P85D has it.

 

[Droschke]

There are rumors that the software locked packs won’t last as long because they never balance (because they never max charge). I don’t think they have been substantiated.

Balancing used to only happen at a higher SoC, but some years ago Tesla revamped the BMS and it balances as needed across almost the whole SoC range based on accurate data calculated for each brick.

 

[ucmndd]

Are you sure all RWD cars have the large rear drive motor? I thought it was just the Performance cars that had it, 2wd & 4wd. My P85D has it.

I’m sure. There are performance and non-performance versions of the large drive unit, but the only difference is the inverter. All RWD cars have the large DU, performance or not.

 

[UberDad]

I'm on the very same hunt as the OP.
After talking to my insurance agent (State Farm), and a bunch of research, I think I've landed on my "ideal" configuration: 2016.5 Model S 75D with HW1; The 75D has lower insurance rates vs all of the other configurations, the more reliable motors, decent range that's almost as good as the 85kWh pack. And of course the FUSC option. I also think I would prefer the AP1 Autopilot hardware due the presence of the radar and the lower cost vs a "Unicorn" version with AP2. If anyone is selling one like this please reach out!

 

[DerbyDave]

I believe the radar is unused even in the earlier models. Tesla went to Tesla vision on all software versions some time ago.

 

[ucmndd]

I believe the radar is unused even in the earlier models. Tesla went to Tesla vision on all software versions some time ago.

AP1 still uses radar and always will. It won’t work without it.

 

[Tam]

I believe the radar is unused even in the earlier models. Tesla went to Tesla vision on all software versions some time ago.

Radar is still active as mentioned in AP1.

In addition, for AP2 and above:

Those with MCU1.

Those with less than HW3.

Those with less than V2.5 cameras even when upgraded to MCU2 and HW3.