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Automatic service call generated 12v battery
- Thread starter mike123abc
- Start date
AlanSubie4Life
Efficiency Obsessed Member
Interesting. A lot higher capacity than most of the available LiFePO4 batteries.
How do they do in well below 0F temperatures? I thought that was one reason the lead acid still does reasonably well (although they too can struggle with cranking amps - not relevant here of course - in the cold). But the below 0F performance would be relevant to a lot of Model 3 owners. Though not me. So maybe I should consider this in future...save some weight!
Yes if I knew this lithium ion 12v battery would perform well in the cold weather, I wouldn't mind buying one. It would be so much more convenient if Tesla used a standard 12v so we could just pick one up at a local auto parts store when needed. Looks like the Interstate MT-51R is a close fit, but might be a hair too big.
I may just buy a spare from the SC and keep it in my garage.
I may just buy a spare from the SC and keep it in my garage.
Glamisduner
Active Member
Trailer repair place killed my 6v batteries by accidentally pulling out the emergency brake pin with their forklift. The guy tried to tell us it was good for the batteries no matter how much I argued. I put them on the charger and a couple hours later smoke was pouring out of one one them.
ElectricLove
Member
The well below 0F temperatures are definitely hard on any battery, the good thing with the teslas is that in the extreme cold there isn't much being asked of the 12v battery. When the car is up and "running" in the extreme cold there is a lot of energy being dumped out of the main battery pack on keeping itself warm and some of that warmth radiates to the 12v and other ancillaries, so during operation the 12v gets a little warmer (not nearly as warm as the main traction battery of course but it does get some). Also, when plugged in and especially supercharging the main-pack warming system is pumping out heat. So that tends to keep the 12v warmer than you might suspect based on climate alone.
And another key point; LiFePO4 batteries are better in the extreme cold than the "typical" lithium-ion batteries (like whats in the main-pack of the tesla). Extreme cold doesn't bother them at all for discharge (reduces cranking amps but that isn't relevant for an EV), but it does cause premature fatigue on the battery if it is charged in the extreme cold. Fortunately the TESLA doesn't aggressively charge the 12V in "most" extreme cold situations because during times when the 12v is "extreme cold" the main-pack is "extreme cold" and that means if the car is "on" it is dumping a lot of power into its warming systems.
Now, of course there are, worst case situations where it gets below -20F overnight and the owner truly can't or just doesn't bother to keep the car in a garage or plugged in... Two things happen there; 1. Read your warranty from TESLA because they could void the main-pack warranty in this case and 2. the LiFePO4 won't get much "charge" current (if any) from the main-pack because the car isn't "on".
I won't say that the LiFePO4 is unaffected by the cold but I will say that in the tesla there are a few things that line up just right that make it work really well despite extreme cold situations. I would still suggest that the LiFePO4 is going to suffer some of its longevity for every day it has to put up with "extreme cold", however the nice thing is that it isn't likely to altogether fail, so it means instead of 5 years of life you get 4 or maybe 3... But in the end you will still fair better than the OEM Lead batteries...
Well on another note, I was on the phone with Tesla service about my 2/21 appointment and seeing if I could get in sooner when the Rangers texted me that they see I need service quicker and offered me service on 2/14 (Thursday) 8AM. The service guy claims that he was not in contact with the rangers at the time, just a coincidence? Anyways the Tesla will spend a week less in my garage.
The service guy said the Plano, TX service center did not have any batteries available. But, the rangers had them. He was trying to arrange the rangers to drop one off at the service center so I could get it replaced when the Rangers texted me moving up my new appointment.
They also said that my model 3 had a steering bolt technical service bulletin to take care of at the same time. Maybe that is why I am always fighting the autopilot that my hands are on the steering wheel. It is a delicate balance between jerking the wheel out of EAP and getting the warning to go away.
My car is sitting in the garage with the frunk open and the driver's window down. When the battery goes dead you cannot get into the car except to do the front jump thing then charge the battery to get the door handles to work. I am borrowing a minivan from my dad while I wait for service. After driving the M3 for 6 months, it is hard to go back to ICE. I keep waiting for brake when I take my foot off the accelerator. Then I have to keep my foot on the break... Oh the woes of going back!
The service guy said the Plano, TX service center did not have any batteries available. But, the rangers had them. He was trying to arrange the rangers to drop one off at the service center so I could get it replaced when the Rangers texted me moving up my new appointment.
They also said that my model 3 had a steering bolt technical service bulletin to take care of at the same time. Maybe that is why I am always fighting the autopilot that my hands are on the steering wheel. It is a delicate balance between jerking the wheel out of EAP and getting the warning to go away.
My car is sitting in the garage with the frunk open and the driver's window down. When the battery goes dead you cannot get into the car except to do the front jump thing then charge the battery to get the door handles to work. I am borrowing a minivan from my dad while I wait for service. After driving the M3 for 6 months, it is hard to go back to ICE. I keep waiting for brake when I take my foot off the accelerator. Then I have to keep my foot on the break... Oh the woes of going back!
AlanSubie4Life
Efficiency Obsessed Member
Hmm. From what we (think) we know about vampire drain, it sounds like even when plugged in, the 12V will be discharged at perhaps 5W. Then every now and again the car will wake up, warm up the HV battery (which will energize the 12V "rail" and start charging the 12V to top it up), and then finally top up the HV battery. So it seems like the LiFePO4 battery would get charged when it is below freezing on every cycle (I said well below freezing, 0F, but wonder what the effect is of being charged in temps below 32F). I understand you say it might warm up more than you think due to the other warming going on...but after a good day or two of cold soaking it's going to be pretty chilly up there near the hood, and the 12V will start getting charged as soon as the contactors close! As you say, chemistry is not the same as the traction battery (which will get lithium plating if charged below freezing) but I have no idea how much different the effect is for LiFePO4.
Seems like if you kept your car in the garage most of the time when not being driven, it might be fine.
In any case seems like it could be a good future option for me. But still seems a bit questionable for colder climates. It kind of seems like the 12V AGMs might last 5 years, based on the 5000 cycle counts with 10% discharge (which is terrible of course for such a nice battery), but the LiFePO4 might not be better in the colder situation. Obviously the OP's did not last 5 years. One guy in my office had to have his replaced as well. But they seem like "infant mortality" failures.
I think that they must have had a bad batch. When mine was in the delivery pipeline a lot were complaining that their cars were held up from delivery because of failed 12v batteries (August 2018).
jkoya
NA2 NSX
There is a YouTube video that shows you can open the frunk using a 9V battery when the 12V battery is dead.
StealthP3D
Well-Known Member
I disagree, in the extreme cold, the battery life of the lead-acid AGM will be better than the LiFePO4. That's why Tesla chose the AGM.
StealthP3D
Well-Known Member
Like all manufactured items, there is a small percent of defective batteries that fail in the first year. They are replaced under warranty. Tesla specified a larger battery for the Model 3 compared to the Model S which should make it last longer due to smaller depth of discharges.
AlanSubie4Life
Efficiency Obsessed Member
The car keeps the battery charged even when you’re not driving it (the drain is about two orders of magnitude higher than a properly designed ICE vehicle, so it is essential to do this)! It is not necessary to drive the car.
I have looked at 12V backups but I gave up because they seem like a huge pain to keep charged, and several reviews for the many products on Amazon suggest they will catch on fire or explode, possibly when unattended, so I am not taking my chances with that. I’m also not sure they would even temporarily resolve a 12V battery issue. And it would likely be inaccessible if you needed it.
I just got a bicycle pump for my tires, so I don’t have to worry about blowing the 12V/12A outlet electronic fuse, and I have AAA (or maybe Tesla, but not counting on that in the middle of nowhere) if the battery dies.
Well an update. The Tesla Ranger came out with a new battery this morning. Same brand/model, just the date was 11 weeks newer.
He then did a couple of service bulletins:
1. Worked on the frunk latch to be sure it closed properly and easily. Mine was aligned and worked fine without adjustment
2. Put on the Dual Motor badge
Looks like Tesla 3D printed the Dual Motor badge alignment tool.
I had mixed feelings about the badge. On the one hand I like the clean look without it, but on the other sometimes you need AWD or chains when I visit snow country.
He had a Ford van
He said they could not have Model X's since they lacked superchargers in the area.
He also did an automatic window calibration, essentially he plugged in his laptop and the windows went up and down in a pattern.
Another interesting thing that I did not notice on the battery until it was out is that there is a vent tube on the side to keep out gasses from building up in the car.
He also checked the tire pressure.
He then did a couple of service bulletins:
1. Worked on the frunk latch to be sure it closed properly and easily. Mine was aligned and worked fine without adjustment
2. Put on the Dual Motor badge
Looks like Tesla 3D printed the Dual Motor badge alignment tool.
I had mixed feelings about the badge. On the one hand I like the clean look without it, but on the other sometimes you need AWD or chains when I visit snow country.
He had a Ford van
He said they could not have Model X's since they lacked superchargers in the area.
He also did an automatic window calibration, essentially he plugged in his laptop and the windows went up and down in a pattern.
Another interesting thing that I did not notice on the battery until it was out is that there is a vent tube on the side to keep out gasses from building up in the car.
He also checked the tire pressure.
Smart, I got the Tesla tire patch/pump kit, but might keep a manual pump instead. I will keep up AAA backup also with the hopes that they will be more Tesla/EV friendly
Some ice cars can be "jumped" using the 12V/12A outlet from the car itself. Impossible with Tesla due to the drain is about two orders of magnitude higher? Also what is the average/warranted life for the it?
AlanSubie4Life
Efficiency Obsessed Member
I know very little about either of these things (can't imagine you can jump an ICE from the car itself...because the 12V would be dead...and it can't supply the current). All I can say is the cranking amps and drain on the 12V battery is far far higher in an ICE during that brief moment of time, than it is in a Tesla at any time. The draw on the Tesla 12V just isn't going to be very much compared to an ICE starting load. What I meant with the "orders of magnitude" was in reference to the standby drain (which is nearly non-existent on a non-defective ICE, but relatively high for Tesla (3-5W in sleep it sounds like based on some data someone posted from a battery tender)).
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