2014 P85d High Voltage Failure

[mr_hyde]

Unfortunately, I ended up with a HV battery failure last night – 2014 P85D. There were buckets of errors on the screen mostly related to a dead 12v which I hoped was the issue so I replace it. When the car came back on, the errors persisted. ScanMyTesla shows Cell 46 down over a volt and Cell 47 and 48 aren’t listing at all.

Now, I need to decide what to do. I will not pay Tesla for a ‘refurbished’ pack and I can’t justify the money for a new pack. I would like to keep the car because it is in great condition otherwise. I normally do all of my own work including replacing engines and transmissions in ICE cars but I don’t have a lift or easy access to one. I’m in Seattle so none of the usual suspects are close geographically.

Suggestions? What does it mean when once cell is down and two more are simply missing from the list? It seems more likely to be a control issue than an actual battery chemistry issue. The last time I looked, my imbalance was .14 and everything on this list are between 3.920 and 3.924. Fun fact – the original owner says the pack was replaced in 2015 but there is no sticker on it.

 

[brainhouston]

what were the codes?
could be sense wire fell off... common for older packs or bmb pcb
get used pack or the whole wrecked car with good pack, they are cheaper than reman Tesla pack nowdays.
if u were closer i'd help u

 

[mr_hyde]

There were buckets of codes with many of them related to the 12v peeing down its leg when the HV wouldn't keep it going.

 

[DerbyDave]

this sucks....

 

[brainhouston]

Yeap, 107 def points to sense wires.
I think someone else posted on here with similar experience

 

[NV Ray]

Yeap, 107 def points to sense wires.
I think someone else posted on here with similar experience

Over in the FB BMS_u029 Group.

 

[NV Ray]

You're 029/018 alert solution will likely depend on what you want to do with your car and your personal finances. My advice, and I'm just one person, is based on personally talking with hundreds of folks and my own experience. I don't profess to be the expert.

So, unless you're mechanically inclined and comfortable around higher voltage - (1) If you love the car and want to keep it less than 3 years, either get a remanufactured pack replacement or fix of your current pack for $7k-$15k, (2) if you like your car and want to keep it for more than 3 years then get new pack from Tesla for $20k, (3) If you're done with Tesla and just want to walk away, sell your car for $7k-10k with known 029/018 alert.

If you're mechanically inclined, then you can swap packs or attempt to repair your existing pack.

 

[howardc64]

Helping OP (lives nearby) with the MS. Trying to guess if the fault is likely voltage sense wire contact to 74P plates or on the BMB before any disassembly.

Does anyone know if brick 46-48 voltage sensor wire contacts are all on one side of module 8? I'd imagine there are either 6 or 7 voltage sensing wires for a 6S74P design. So likely some wires on top of module and some on bottom. Wondering if 46-48 are all on one side which would then suggest moisture related wire to 74P plate contacts failure rather than on BMB.

 

[mr_hyde]

I'm inclined to try to repair this pack but will need to research more about what is involved with the sensing wires vs replacing a BMB board. It seems likely that there is moisture in there precipitating this so hopefully it isn't too wide-spread. If I DIY, I would spend MANY hours cleaning and prepping the two surfaces and would be tempted to hose the whole thing down with some kind of industrial Flex-Seal when it was back together.

 

[brainhouston]

have a look here:

TESLA MODEL S stopped working... CAR MAY NOT RESTART

It’s not due to recent software updates. I got the same errors last year and they’re too generic to always map to a specific issue. Remote diags pointed to failing battery coolant heater as well so it was replaced under warranty. If you’re up for a DIY replacement, the HV piece shouldn’t scare...

teslamotorsclub.com

 

[Krash]

Side note. I know you want a performance battery, because you have a performance car, but if the battery died, couldn’t you pull two of the modules from the 400v performance battery and end up with a 350v battery and a drivable car for a while, while you looked for a better battery?

 

[howardc64]

Side note. I know you want a performance battery, because you have a performance car, but if the battery died, couldn’t you pull two of the modules from the 400v performance battery and end up with a 350v battery and a drivable car for a while, while you looked for a better battery?

Interesting option. Are there programming / pack configuration requirements? If so, what tools are necessary?

 

[brainhouston]

Side note. I know you want a performance battery, because you have a performance car, but if the battery died, couldn’t you pull two of the modules from the 400v performance battery and end up with a 350v battery and a drivable car for a while, while you looked for a better battery?

You at least need some bus bars n wiring cause u have to bypass 2 modules n remove 2 BMBs from the loop
I'd imagine u also need to somehow re-flash the BMS...
Pretty sure thats what ReCell does n they mentioned some "secret sauce" needed...

This would be a great DIY solution to many i'm sure if only someone shared how its done

 

[mr_hyde]

You at least need some bus bars n wiring cause u have to bypass 2 modules n remove 2 BMBs from the loop
I'd imagine u also need to somehow re-flash the BMS...
Pretty sure thats what ReCell does n they mentioned some "secret sauce" needed...

This would be a great DIY solution to many i'm sure if only someone shared how its done

It sounds like this is exactly what recell does which concerns me. I don’t need a 2.3 second launch to freeway speeds but I don’t want range to take a hit. I’m also concerned how I market the 14 module pack to a prospective buyer if I choose to sell at some point. If I was a buyer, I would walk away from that car if a working ‘full’ pack car was available.

 

[brainhouston]

It sounds like this is exactly what recell does which concerns me. I don’t need a 2.3 second launch to freeway speeds but I don’t want range to take a hit. I’m also concerned how I market the 14 module pack to a prospective buyer if I choose to sell at some point. If I was a buyer, I would walk away from that car if a working ‘full’ pack car was available.

14 module pack is a legit Tesla pack aka 70kWh used on 70D. in this case it would just be DIY, but yeah it decreases value of car
later it was 90kWh for 16 n 75kWh for 14 modules with upgraded chemistry
now Tesla only uses modules from 100kWh pack so 14 module became 90kWh 350V pack

 

[mr_hyde]

14 module pack is a legit Tesla pack aka 70kWh used on 70D. in this case it would just be DIY, but yeah it decreases value of car
later it was 90kWh for 16 n 75kWh for 14 modules with upgraded chemistry
now Tesla only uses modules from 100kWh pack so 14 module became 90kWh 350V pack

So when Recell is offering a 240 mile battery with presumably 14 modules, they are using upgraded chemistry. When I look at their offerings, I would absolutely do the longer range for the $1,500 price difference. In real world driving, I find myself wishing I had slightly more range once or twice a month - going on a hike in the mountains for example.

 

[brainhouston]

So when Recell is offering a 240 mile battery with presumably 14 modules, they are using upgraded chemistry. When I look at their offerings, I would absolutely do the longer range for the $1,500 price difference. In real world driving, I find myself wishing I had slightly more range once or twice a month - going on a hike in the mountains for example.

i honestly don't know what they use, they don't reveal that info n i don't think anyone opened their reman pack yet...
i also hear that 90kWh packs degrade faster than 85kWh packs so at this age modules might have same CAC..
they might just be sorting modules by CAC, leave best ones for 240+ packs.. or maybe they use 100kWh modules but i doubt it, not enough of those around

my 90kWh ver3 pack has 76.7kWh left at this age.. not sure what that would equal to in S as a 14 module one...

simple math would mean ~66kwh as 14
on facebook they recently stated their 210+ needs to have 59.9kWh at least ...

 

[mr_hyde]

I'm not sure what my pack was actually putting out - I didn't check or do the math before the failure. I was under 180 miles at 80% which was less than it should have been I think. I would get to almost 220 at 100% although I only did that a few times experimentally. If the range of the 240+ pack actually showed that on my car, it would be an improvement. Maybe that was a sign of faster degradation.

 

[howardc64]

Some interesting updates on OPs battery. brick 45 went down 200mV (3.9 to 3.7) in 1/2 hour with car tilted one way (driver side up) and back up 200mV with passenger side up. Sounds definitely like liquid inside.

200mV on a 74p 18650 group is serious amount of energy if really discharged in 1/2 hour.

 

[brainhouston]

so sounds like water got in the module tray
this way its shorting 2 brick plates but that should drain 2 bricks...
i made a sketch of that scenario in this post:

https://teslamotorsclub.com/tmc/posts/7522790/bookmark

something not adding up... is other 2 bricks still not showing up?