My 2 day old P85D suddenly died in the middle of an intersection

[mknox]

Any thoughts on what happened?

Sounds like that main contactor failure that's been talked about so much here. Once the main battery disconnects, there is no DC-DC conversion to power the 12v which seems to die very quickly when not being "topped up" constantly.

 

[ecarfan]

@osama, sorry to hear about your problem and glad you and your son are okay given the brutal weather (I used to live in Toronto and worked for a company in North York, so I know what it's like!).

I still am not clear on why Teslas have a conventional 12V battery.

My 1.5 Roadster does not have a 12V battery but I understand that the 2.0 and later do have 12V batteries.

 

[osama]

Sounds like that main contactor failure that's been talked about so much here. Once the main battery disconnects, there is no DC-DC conversion to power the 12v which seems to die very quickly when not being "topped up" constantly.

I have read this thread and it describes EXACTLY what happened to me. Thank you so much for posting this. I guess I will be needing a new battery pack? Are these things usually in stock?

 

[GetAmped]

@ Osama

Again sorry to hear about the failure. I noticed in the photo that the door handle lights are on, do these work if the 12v is dead?

 

[stevezzzz]

I don't know how many E packs there are I stock at service centers yet. When my A pack contractors failed, it was a simple matter for the Denver SC to swap in a refurbed pack they had on hand. You can read about it here...

http://www.teslamotorsclub.com/showthread.php/37269-The-Dreaded-Clunk-and-a-great-service-experience

 

[David99]

HThe music is Slacker "Today's hits". I guess my wife picked when she last drove the car.
Any thoughts on what happened?

My guess is there was a 'One Direction' song playing and the car just couldn't take it. LOL

 

[osama]

@ Osama

Again sorry to hear about the failure. I noticed in the photo that the door handle lights are on, do these work if the 12v is dead?

Yes ... the door handles and 4-way flashers still work with a dead 12V although the door handles do not auto-present. You have to push them to open the door.

 

[mknox]

I noticed in the photo that the door handle lights are on, do these work if the 12v is dead?

Probably came back to life when the 12v was boosted to release the electric brake.

 

[David99]

I still am not clear on why Teslas have a conventional 12V battery.

All on board electronics in cars are built for 12 Volt. Pretty much anything electrical in cars is 12 Volt (whipers, pumps, lights, cable configurations, computers, dash board instruments, main lights, audio system, ...) . If you change that, you have to custom build every electrical part which would be a major PITA and more expensive. It would also be very dangerous to have 400 Volt all over the car. So running everything on a safe 12 Volt level makes a lot of sense. Haveing a separate 12 Volt battery is also a good idea because you can run all electronics independent of the main pack.

The issue isn't the separate 12 Volt system, the problem is that Tesla has some bugs keeping the 12 Volt battery charged at all times. In an ICE car the generator charges the battery as soon as the engine runs. Tesla has a DC/DC converter that converts the 400 Volt main pack voltage to the 12 Volt needed. For some reason it doesn't work properly sometimes.

 

[AudubonB]

This discussion about 12V batteries failing is a head-scratcher for me. I have lived decades in some of the coldest parts of this continent, keeping a fleet of about a dozen vehicles. I never have had a lead-acid battery let me down. Sure, I have had them unable to crank out the needed amps at negative-hell-and-gone - that is absolutely par for the course. But -12ºC is NOT "cold", by lead-acid, and particularly NEW lead-acid, battery standards.

Now, if I lived in Miami - or spent my summers in Arizona :tongue: - I know that heat is a killer for Pb-acid cells. But the relatively frequent tales of dead 12Vs crippling Model Ss is a real mystery. What could be different about these from the batteries that have been maintaining ICEs for so many decades?

As an aside, as reliable as (I think) Pb-acid batteries are in the cold, as far as I am concerned, the real Achilles heel for Tesla at present is the utter inappropriateness of Li-ion technology in frigid climates. I am absolutely hoping we (Tesla) achieves an electrochemical breakthrough before they begin marketing a pickup truck - elsewise, no Alaska market for them. They'll have to confine themselves to Texas (horrors).

 

[NuclearPowered]

One of my Prius' 12v systems has been running on an $18 lawnmower battery from walmart for quite some time now. Surprised that Tesla still cant get these 12v system failures under control.

 

[stevezzzz]

Hang on, folks: we're not seeing a 12V battery failure here, we're seeing a 12V battery that discharges normally, under load, after a main traction pack failure prevents it from recharging the 12V.

This is a totally different issue from the 12V failures we were seeing in the first year after the S was released: that seems to have been a combination of substandard 12V batteries from a supplier and inadequate software in the DC-to-to-DC converter system.

 

[osama]

Hang on, folks: we're not seeing a 12V battery failure here, we're seeing a 12V battery that discharges normally, under load, after a main traction pack failure prevents it from recharging the 12V.

This is a totally different issue from the 12V failures we were seeing in the first year after the S was released: that seems to have been a combination of substandard 12V batteries from a supplier and inadequate software in the DC-to-to-DC converter system.

Agreed Stevezzzz ... But why is this still happening? And how do I know that my other car isn't going to breakdown too? Does Tesla acknowledge that it has a problem with the traction pack?

 

[Saghost]

This discussion about 12V batteries failing is a head-scratcher for me. I have lived decades in some of the coldest parts of this continent, keeping a fleet of about a dozen vehicles. I never have had a lead-acid battery let me down. Sure, I have had them unable to crank out the needed amps at negative-hell-and-gone - that is absolutely par for the course. But -12ºC is NOT "cold", by lead-acid, and particularly NEW lead-acid, battery standards.

Now, if I lived in Miami - or spent my summers in Arizona :tongue: - I know that heat is a killer for Pb-acid cells. But the relatively frequent tales of dead 12Vs crippling Model Ss is a real mystery. What could be different about these from the batteries that have been maintaining ICEs for so many decades?

As an aside, as reliable as (I think) Pb-acid batteries are in the cold, as far as I am concerned, the real Achilles heel for Tesla at present is the utter inappropriateness of Li-ion technology in frigid climates. I am absolutely hoping we (Tesla) achieves an electrochemical breakthrough before they begin marketing a pickup truck - elsewise, no Alaska market for them. They'll have to confine themselves to Texas (horrors).

Two reasons, I think. First, from what I've read Tesla has opted for a rather small 12V battery (described in several older posts as a motorcycle battery, AFAIK it's still the same.) They presumably did this because they figured that there's no engine to crank, and the DC-DC converter is nearly always available to support the battery. 99% of the time, this logic was correct - but it leaves them with less reserve when things go wrong.

Second, I think a lot of the '12 V failures' are actually secondary failures. Yes, the twelve volt battery is unquestionably discharged after the car stops - but a lot of the time I think this is the result of some other failure that caused the contactors to open and the DC-DC converter to shut down. I'm not certain, but I suspect the 'twelve volt low' warning down above is like the battery light in a lot of cars - an indication that the alternator (DC-DC converter) isn't charging the battery and it is sitting at ~12V rather than that the battery is dead then (because the computers won't run with the twelve volt battery dead.)
Walter

 

[Xenoilphobe]

I have replaced all our cars batteries with Odyssey Batteries - haven't done it in the Tesla yet because it is so new..

http://www.odysseybattery.com/design_advantages.aspx

 

[Raffy.Roma]

@osama

I am sorry for what happened to you. I am sure that Tesla will fix your Model S readily.

 

[GetAmped]

Agreed Stevezzzz ... But why is this still happening? And how do I know that my other car isn't going to breakdown too? Does Tesla acknowledge that it has a problem with the traction pack?

What is the "Traction Pack"?

 

[dsm363]

What is the "Traction Pack"?

The big 60 or 85kWh pack.

 

[gpetti]

Two reasons, I think. First, from what I've read Tesla has opted for a rather small 12V battery (described in several older posts as a motorcycle battery, AFAIK it's still the same.) They presumably did this because they figured that there's no engine to crank, and the DC-DC converter is nearly always available to support the battery. 99% of the time, this logic was correct - but it leaves them with less reserve when things go wrong.

Second, I think a lot of the '12 V failures' are actually secondary failures. Yes, the twelve volt battery is unquestionably discharged after the car stops - but a lot of the time I think this is the result of some other failure that caused the contactors to open and the DC-DC converter to shut down. I'm not certain, but I suspect the 'twelve volt low' warning down above is like the battery light in a lot of cars - an indication that the alternator (DC-DC converter) isn't charging the battery and it is sitting at ~12V rather than that the battery is dead then (because the computers won't run with the twelve volt battery dead.)
Walter

One thing I discovered with my car is that if the car detects any kind of a short or problem on the 12V "bus" then it can isolate the 12V system from the main battery pack - or at least that is roughly what I was told by a ranger. I had a similar warning but fortunately at a point when I wasn't in motion - sitting in a parking lot. I had the heater on and apparently the heating unit had an intermittent problem that was causing the 12V to be disconnected from its main battery supply. With the heater off and a re-boot I was able to use it. Ultimately the ranger replaced the faulty heating unit and the 12V battery for good measure.

 

[stevezzzz]

Agreed Stevezzzz ... But why is this still happening? And how do I know that my other car isn't going to breakdown too? Does Tesla acknowledge that it has a problem with the traction pack?

Since sudden, total pack failures have been happening with some regularity since day one, you'd think Tesla would have sorted this problem out by now, so that the E packs in the flagship P85D would have the very latest mods and the smallest probability of failure. And yet, here you are...

There's another thread that talks about proactive pack upgrades being performed at SCs in recent weeks. Some of the SCs are now trained and equipped to open traction packs and perform the mods; others are not, apparently.