Options for bad battery

[PAFDenver]

Tesla service is saying my 2013 Model S P85 needs an HV battery replacement. I had asked them to investigate a strange error that started getting after they replaced the drive unit and forgot to properly purge (best case) the coolant. This is very disappointing as the car only has 35K miles on it, was well kept and has fewer than half a dozen high voltage charges on it. I normally only charged to 80%. I don't see much range degradation - I am still getting 220+ miles at the 80% limit.

There's no way I am replacing the battery at $22K so I am debating the options in front of me. The realistic options I see are:
1. Sell the car
2. Donate the car
3. Take it to an independent shop to get the weak battery modules replaced
4. Live with it until it dies

Am I missing any other good options?

I expect selling or donating the car will yield practically nothing (since I would disclose the battery issue) so the current valuation ($35-40K maybe) would drop down to $10-15K or less. So not very enticing, although I would actually prefer this option. I an assuming that I would lose the cost of replacement ($22K), or more, if sold as-is. Or would selling it with a brand new, warrantied battery add significant value to the current price range and really only impact the selling price by $5-10K? Obviously no one knows, so asking for speculation.

Does anyone know about the longevity of having an independent shop replace the bad cells/modules? My fear is that all the cells are starting to fail and if I replace the bad ones now, in 6 months I will have more cells failing and will be back to where I am now. Will the older, weaker cells that remain overly stress the new batteries installed?

The most likely option is the last one, just living with it as-is. I don't drive that much and when I do, it's short trips in town, normally 10-20 miles. I might make the occasional trip of 75+ miles, but maybe once per year and for that I have a second car I could use instead. As I see it, I could still use this car until it's range drops down to 40 miles or so, which I think could be many years from now.

Is it SAFE to do that? Will the weak cells somehow cause a catastrophic (i.e. fire!) failure during use or charging (level 2)? Or could they damage the other good cells? I expect that as the number of weak cells increase I will see more weak cells and reduced max power output as well as range. Are there other dangers I should be aware of?
What else am I not considering?

I hope I didn't miss this topic in previous posts, but I searched and didn't see anything really like this. Thanks for your help!

 

[serendipitous]

If you otherwise are happy with the car, I would certainly lean toward the independent shop. Reason being - I'd be suspicious that the HV pack is actually the issue or if it is, that it isn't a small component of the pack. Based on your symptoms that there's an error message but it otherwise seems fine, it doesn't sound like some kind of catastrophic failure. Tesla will say anything and just replace the whole car - they have no incentive to help you find the cause and even if your service center wanted to be helpful, they aren't going to replace a $5 fuse on a lark - they have a procedure to drop the whole pack, put a refurb in, and ask for $22k and send you on your way.

Worst case, the independent shop confirms that it really is a total HV failure, and they would be able to replace the pack for far less than Tesla, albeit maybe without Tesla's 1 year warranty on replacement parts.

 

[PAFDenver]

Thanks Serendiptous, I hadn't thought of that. Any thoughts on how to FIND an independent shop that will work on Teslas? I only know of Rich Rebuild's garages and I found one other place in Phoenix that will do the battery repair (vs replacement). I am in Denver, so a decent sized city, but I haven't hit on the magic search term - or there aren't any independent shops near here.
I suspect that Tesla actually caused the issue. When I went to pick up the car after they replaced the drive unit it immediately through an error about battery cooling. I hadn't even put it in drive yet! They said they did 3 coolant flushes to remove some extra air in the system. I wonder if they got it all, or worse, they actually forgot to fill the system at all. So I would like to get the system flushed by an independent company, but don't know who.
I appreciate the help.

 

[serendipitous]

Gruber is the famous shop in Arizona, and @wk057 's shop in NC - 057 Technology are the two I'm familiar with. I tagged wk057 in this post which might call his attention here - he's certainly a resident expert whose opinion will be far more valuable than mine, and I've seen many happy customers in his For Sale threads when he posts batteries available for swap/upgrades.

 

[wk057]

We have battery replacement options available that have a net cost of well under Tesla's pricing... generally in the $5k range, depending on the actual issue with the pack.

We're a little backlogged on those at the moment, but catching up.

While not useful right this second, we have a product launching soon (hopefully this weekend) that should be an excellent option for owners of out-of-warranty S's, so keep an eye out for that.

 

[PAFDenver]

Thanks guys! Found out that it's just the shunt resistor that failed. Still researching this, but I actually think that is more hopeful than the cells started to call it quits. That aligns better with the relative lack in degradation of range I am seeing
I am seeing used ones on eBay fairly cheap, although I would really prefer new stock. But the real issue is actually removing & installing it. I need to get the car to someone who can DO the repair.
I also need to figure out the implications & limitations for using the car until I get it fixed. I dropped my home charging limit down to 20A and will be a bit more careful about stomping on the accelerator pedal. Not sure if it's safe to fast charge if I was to make a road trip to Phoenix.
WK57 - I assume your shop is located in NC? Can you get OEM parts (like maybe a shunt module for example...)?

Again, thanks for all your help - it is truly appreciated.

The funny thing is a couple of months ago I was considering sending a message to RJ Scaringe (CEO of Rivian) highlighting that a crucial aspect of the success of Rivian will be service and repair. And more than just having their mobile fleet of techs, but actually enabling independent mechanics to fix their vehicles. Maybe I will revisit doing that. It really is a weak link in the conversion to EVs and needs to be addressed.

 

[wk057]

I forgot to post my usual warning that replacing individual modules within the pack, or removing individual cells, etc aren't real fixes. Check out my other posts on the topic. Eventually will have to do a full writeup on this.

 

[PAFDenver]

wk057 - I found your description of the shunt board in another post on here. I am trying to understand the implications of just living with the car as. Per Tesla my "HV battery pack shunt has failed". The car is still driving fine although I am taking it easy on acceleration and dropped my current limit for home charging (although I now suspect that's unnecessary). As I understand it the purpose of the shunt board is to just measure the total current coming from the battery and transmit value that to the BMS controller. Is that right? Is it only measuring current flowing from the battery or is also measuring current during recharge? I'm not finding much detailed information on the role of the shunt resistor.
The error I saw that started this is weird. I live in CO so it's pretty normal to start out with reduced regen because it's cool in the garage. As I drive, I get more and more regen until the limit bar disappears. What I now see (although it didn't happen today or yesterday after picking it up from Tesla) is that just as the regen limit bar is about to disappear, I get an error saying that I have reduced regen and power and BOTH the regen limit and max power output bars show up as if the car was VERY cold. But over the next ~30 seconds they both increase (more regen & power output) until they disappear completely.
That's the only error I see and it's very occasional. I am surprised that if this really has failed (open/short) that the car wouldn't be screaming at me to pull over immediately as it doesn't know what's happening with the battery. But so far it's happy to let me drive without any issues except that weird, occasional error when limited regen disappears.
What are the dangers/issues you see for just living with this? Is this critical to the charge system - that's my single biggest concern actually?
I have no indications that any of the individual modules are bad, so I expect this is a fixable issue. Unfortunately it requires a huge amount of labor (dropping the battery pack), but I can't see any reason why it's not possible to do. Do you? Does your company do repairs like this? If so, would you be able to give a ballpark estimate? Unfortunately getting the car to NC is a bit of a challenge too.
Thanks for all your help. I hate asking for all this free advice, but you seem to have lots of experience with this.

 

[wk057]

The shunt measures current in and out of the pack during usage/regen/charging/etc. It's used for capacity measurements, keeping usage and regen within limits, etc. Depending on the failure mode, you could live with it without much issue. If it's completely failed or is grossly misreporting things, you'll start running into major issues (like, range dropping to nothing without warning, or vehicle shutdowns under load). It's usually a 'fix it as soon as practical' level concern, since it can lead to bigger issues down the road if left unchecked... again, depending on the nature of the underlying issue.

We can do the repair if needed, but you might be better off with Tesla on this one since it's a repair they should be able to do without a full pack replacement.

 

[ucmndd]

We can do the repair if needed, but you might be better off with Tesla on this one since it's a repair they should be able to do without a full pack replacement.

I just want to mention that I really appreciate this sort of integrity and customer-first principle. Not a lot of businesses are willing to say “I could do this for you, but you might be better off somewhere else.”

The ones that do, though, those are the ones I’ll seek out every time.

 

[DRasheed]

Thanks guys! Found out that it's just the shunt resistor that failed. Still researching this, but I actually think that is more hopeful than the cells started to call it quits. That aligns better with the relative lack in degradation of range I am seeing
I am seeing used ones on eBay fairly cheap, although I would really prefer new stock. But the real issue is actually removing & installing it. I need to get the car to someone who can DO the repair.
I also need to figure out the implications & limitations for using the car until I get it fixed. I dropped my home charging limit down to 20A and will be a bit more careful about stomping on the accelerator pedal. Not sure if it's safe to fast charge if I was to make a road trip to Phoenix.
WK57 - I assume your shop is located in NC? Can you get OEM parts (like maybe a shunt module for example...)?

Again, thanks for all your help - it is truly appreciated.

The funny thing is a couple of months ago I was considering sending a message to RJ Scaringe (CEO of Rivian) highlighting that a crucial aspect of the success of Rivian will be service and repair. And more than just having their mobile fleet of techs, but actually enabling independent mechanics to fix their vehicles. Maybe I will revisit doing that. It really is a weak link in the conversion to EVs and needs to be addressed.

I'm really curious how you found out that it was only a shunt resistor. Did the service center tell you that?

 

[cpaull]

I just want to mention that I really appreciate this sort of integrity and customer-first principle. Not a lot of businesses are willing to say “I could do this for you, but you might be better off somewhere else.”

The ones that do, though, those are the ones I’ll seek out every time.

Yes... I absolutely agree. I just wish @wk057 had a shop closer to the West Coast.
But given this kind of integrity, I am still considering their battery warranty.
They really do seem to be the kind of people you want to give your business to.

 

[wk057]

Yes... I absolutely agree. I just wish @wk057 had a shop closer to the West Coast.
But given this kind of integrity, I am still considering their battery warranty.
They really do seem to be the kind of people you want to give your business to.

Thanks for the kind words all.

We're looking at a bunch of options to save folks costs if/when the time comes for battery replacements, and I'm fully aware that we're not always the best option. Right now cost to ship a vehicle each way to/from California is about $1500. So even when including that vs other options, we usually come out to be a pretty good deal... especially with the new service plan.

Hopefully can keep driving these costs down all around.

 

[3mp_kwh]

Unfortunately it requires a huge amount of labor (dropping the battery pack), but I can't see any reason why it's not possible to do.

RE "huge amount of labor". It sounds like needing the right tools. Packs were designed to come down in minutes. Resister/shunt access may be relatively easy, afterward? Does the part require a handshake, or opening the battery?

For the cases where someone only really needs a lift, or competent shop, maybe save 2k-3k in transport costs?

 

[wk057]

RE "huge amount of labor". It sounds like needing the right tools. Packs were designed to come down in minutes. Resister/shunt access may be relatively easy, afterward? Does the part require a handshake, or opening the battery?

For the cases where someone only really needs a lift, or competent shop, maybe save 2k-3k in transport costs?

First, even if you're able to swap the packs physically, it will just be an expensive paperweight without the knowledge and expertise to properly match them.

Next, Tesla originally thought to make the packs easy to remove and replace as a unit... but that went away pretty quickly (like, 2014-ish), and the S/X packs became more and more tedious to remove/replace. The Model 3/Y packs are a half-day project to remove/replace, not counting any software stuff. Some of the internals are more accessible on the 3/Y from inside the vehicle, but that's about it.

Repairing components inside the S/X packs was originally not even thought to be needed... to the point where Tesla had to cobble together a procedure for replacing contactors at service centers back when the Tyco units were failing left and right. That procedure is a 2-man ~4 hour project. They're sealed, and destructive entry is required to access any of the components internal to the pack like the shunt or contactors.

Tesla has done a lot to make it difficult for these to be serviced by anyone besides their own service folks. Pretty sure I can count the number of places in the world (that aren't Tesla service centers) that could pull off a such a repair on less than both hands.

Long story short, you're not going to take a Tesla to any "competent shop" and get anything useful done with regard to the battery pack. Just isn't going to happen.

 

[TSLA Pilot]

First, even if you're able to swap the packs physically, it will just be an expensive paperweight without the knowledge and expertise to properly match them.

Next, Tesla originally thought to make the packs easy to remove and replace as a unit... but that went away pretty quickly (like, 2014-ish), and the S/X packs became more and more tedious to remove/replace. The Model 3/Y packs are a half-day project to remove/replace, not counting any software stuff. Some of the internals are more accessible on the 3/Y from inside the vehicle, but that's about it.

Repairing components inside the S/X packs was originally not even thought to be needed... to the point where Tesla had to cobble together a procedure for replacing contactors at service centers back when the Tyco units were failing left and right. That procedure is a 2-man ~4 hour project. They're sealed, and destructive entry is required to access any of the components internal to the pack like the shunt or contactors.

Tesla has done a lot to make it difficult for these to be serviced by anyone besides their own service folks. Pretty sure I can count the number of places in the world (that aren't Tesla service centers) that could pull off a such a repair on less than both hands.

Long story short, you're not going to take a Tesla to any "competent shop" and get anything useful done with regard to the battery pack. Just isn't going to happen.

And now that the new Austin MY's have structural battery packs, it makes me wonder if HV battery issues will result in cars that reach End of Life when/if the battery has issues/dies . . . .

Those 4680 cells had better be really, really good!

 

[MP3Mike]

And now that the new Austin MY's have structural battery packs, it makes me wonder if HV battery issues will result in cars that reach End of Life when/if the battery has issues/dies . . . .

Those 4680 cells had better be really, really good!

The pack may be structural, which is more about the cells being structural than the pack, but it is still replaceable, just like the existing 2170 packs. (Tough a little more of the interior may have to come out and be put back with a pack replacement.)