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12v battery needs replacing after 7000 miles/9 months

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I have a late September, 2016 S75. On Saturday I got the "12v battery needs replacement" warning on the dash. I called the Marietta, GA service center as soon as I noticed the message Saturday morning but no one picked up the phone. So I tried again today (Monday) and got someone on the phone. I expressed concern about the 12v battery needing to be replaced after such a short period. I was told that based on charging habits, it can be quite normal for them to only last this long. His tone was indicative of an improper charging regime. So I mentioned that my car has been plugged in 90% of the time but he still said it's normal. I'm not exaggerating when I say the car has been plugged in 90% of its life. Other than maybe a dozen days we've traveled, the car has always been at home and plugged in when not being driven.

Anyway, the tesla guy was just like "well, we have the batteries in stock. when can you swing by?". I pointed out that I live 150 miles from the nearest service center and don't have a break in my schedule large enough for a 300 mile round trip within the next couple of weeks.

So now I'm having to pay just about $500 for a ranger to come out and replace the 12v battery. My question is, are these batteries really only designed to last nine months?

This car has not been driven hard *at all* and there are no accessories in the car. I've made no modifications, etc. I feel like this battery should have at least made it to my one year service checkup. I had already planned on making the trip for that. Would it have really killed them to give me a break on the ranger fee since the battery didn't even last a year?
 
The first 12V battery didn't last long, but I haven't replaced one one for three years now. As the 12V battery gets charged from the main battery, plugging it in or not doesn't make a lot of difference. I'd write a polite letter to the head office and complain about the Ranger fee. They will sometimes do something. There used to be quite a few complaints about this, but it's very infrequent these days (or at least there are far fewer posts).
 
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Sorry but sucks to be you. Unfortunately the 12v battery is a weak spot in Tesla's design. Mine went out after 10k miles. Luckily I was close to a service center, so didn't have to pay for ranger etc. But 12v batteries going out is a very common occurrence - EVEN on the new cars.

Also people far smarter than me have done tests to see why the battery dies so quickly. Basically it's a smaller (like garage door opener size) 12v battery. And Tesla cycles the battery 5-10 times a DAY! So it hits a smaller battery about 10x harder than a normal car. No wonder it dies out. Syonyk's Project Blog: Tesla Model S 12V Battery Analysis

You may get lucky - and your battery may last 4 years or 8 .. but more than likely, compared to a normal car, Tesla's 12v battery will die much much quicker.
 
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Dang, I think I remember reading about your dealings with Marietta when you were buying the car (at least I think it was you). Marietta is my local service center and they always seem to be on top of things when I needed service. Sorry for the nonchalant service you seem to be getting from them. Maybe try the Decatur Service Center?

Can they ship the battery to you and if you are inclined install it yourself? That ranger fee seems ridiculous.
 
I have a late September, 2016 S75. On Saturday I got the "12v battery needs replacement" warning on the dash. I called the Marietta, GA service center as soon as I noticed the message Saturday morning but no one picked up the phone. So I tried again today (Monday) and got someone on the phone. I expressed concern about the 12v battery needing to be replaced after such a short period. I was told that based on charging habits, it can be quite normal for them to only last this long. His tone was indicative of an improper charging regime. So I mentioned that my car has been plugged in 90% of the time but he still said it's normal. I'm not exaggerating when I say the car has been plugged in 90% of its life. Other than maybe a dozen days we've traveled, the car has always been at home and plugged in when not being driven.

Anyway, the tesla guy was just like "well, we have the batteries in stock. when can you swing by?". I pointed out that I live 150 miles from the nearest service center and don't have a break in my schedule large enough for a 300 mile round trip within the next couple of weeks.

So now I'm having to pay just about $500 for a ranger to come out and replace the 12v battery. My question is, are these batteries really only designed to last nine months?

This car has not been driven hard *at all* and there are no accessories in the car. I've made no modifications, etc. I feel like this battery should have at least made it to my one year service checkup. I had already planned on making the trip for that. Would it have really killed them to give me a break on the ranger fee since the battery didn't even last a year?

Remember what actually wears out the 12volt battery on the model s is when you are not driving or charging your car. When your car is running or charging, it is using the DC to DC converter to power 12 volt electronics in the car. When your car is just sitting there doing nothing, even if it is plugged in.. it is cycling the 12volt battery to keep the computers running. To improve 12 volt battery life, drive more, or charge slower and turn on power saving functions so it cycles the battery less when not in use. I have almost 3 years and over 50,000 miles on my current 12volt battery. But I drive a lot. I also charge slowly (using solar). If you plan on leaving the car sitting for a long period of time, use a battery tender to keep the 12volt battery charged (takes a slight bit of modification and a decent sized battery tender). Best of luck to you.
 
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Dang, I think I remember reading about your dealings with Marietta when you were buying the car (at least I think it was you). Marietta is my local service center and they always seem to be on top of things when I needed service. Sorry for the nonchalant service you seem to be getting from them.
Yeah, that was me. They also delivered the car with a messed up from bumper.

Maybe try the Decatur Service Center?
I'll give them a call tomorrow. For some reason, whenever I call the support number, I'm directed to the Marietta location. However, I bet I can find a direct number for Decatur.

Can they ship the battery to you and if you are inclined install it yourself? That ranger fee seems ridiculous.
I'll ask about this. I have no problem installing it myself.

Remember what actually wears out the 12volt battery on the model s is when you are not driving or charging your car. When your car is running or charging, it is using the DC to DC converter to power 12 volt electronics in the car. When your car is just sitting there doing nothing, even if it is plugged in.. it is cycling the 12volt battery to keep the computers running.
Eh, I routinely go 24-48 hours without driving the car (I work from home). So that could be the culprit. Though power saving is on and I don't use any service like TeslaFi that polls the car. It sleeps other than when it wakes up to phone home (usually in the early AM hours).

I'm going to give the Decatur location a call tomorrow and see what that can do.
 
I'm on my original battery; the car is 18 months and has done 25,000 miles. I normally charge it every 3-4 days, mainly because I couldn't be bothered to plug it in at night or unplug it in the morning. The car has been driven daily except when it was shipped to Norway and then to the UAE (each was a journey of 6-7 weeks unplugged).

When I am on leave or away I leave it plugged in and charged around 50% so it gets topped-up every 3 days when sitting idle. Sometimes when travelling for a short business trip I let the car charge on very lower power (5 amps) for up to 2 days until it reaches 90%.
 
Wow, I'm at 9k miles and 6.5 months and no issues (so far...). I do use my car a lot but its also parked frequently with the HVAC on for 1-2 hours since my child will fall asleep while I am driving her back from her grandparent's and its a pain to wake her while extracting her from her car seat (and the car is electric, so no fumes).

Does anyone know if operating it like that affects the car's systems negatively? The car turns itself off after about 10 minutes but the two displays still operate along with the concomitant systems (entertainment, connectivity, HVAC, interior lights, etc). It just isn't drivable (though one brake press and you can shift into gear and go).
 
I'm at 42 months and 58k miles and still on original 12v. They should cover yours under warranty. I can empathize with the drive to a service center (I'm about 100 miles each way) but that is not really Tesla's fault we all knew where service centers were and where they were not when we bought the vehicle. Frustrating but mine had several issues in the first 10k (sensors, instrument clusters, etc) that they fixed for free and it has been pretty great for the last 45k miles.
 
I'm afraid of my battery dying, I read so many horror stories, but I'm 2 years and 60K miles strong (100k miles overall, second owner who knows if this is the original batter though,,,) I plug in every night, not sure if that has something to do with it.
 
I'm going to pander a bit here but if you replace your 12V battery with a Lithium 12V battery this problem goes away, they last much longer and are more appropriate for the usage scenario presented by the TESLA (many cycles, low cranking-amps).

Here is the pandering part; check out BattMobile Batteries! We have this lithium 12V for the TESLA and the reason we developed it (and the entire business) was after this exact same thing happened to me!!! (premature 12V battery failure in a Model S)
 
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It seems we have this resolved. They've offered to waive the ranger fee. I feel this is fair considering past issues and a misaligned door that they've yet to rectify (they want to wait until the yearly inspection). If the 12v battery had even made it a year they would have caught it at the inspection. Dying at nine months/7000 miles is just a tad too soon.

Agreed. I should have mentioned that that only 9 months old, this is just premature. Even if it was never driven and just cycled constantly. I would hope/expect for at least a year under any operating condition. Even that's not good. Hopefully this issue will be designed out in the future cars like I have been hearing.
 
I'm going to pander a bit here but if you replace your 12V battery with a Lithium 12V battery this problem goes away, they last much longer and are more appropriate for the usage scenario presented by the TESLA (many cycles, low cranking-amps).

Here is the pandering part; check out BattMobile Batteries! We have this lithium 12V for the TESLA and the reason we developed it (and the entire business) was after this exact same thing happened to me!!! (premature 12V battery failure in a Model S)
I'll likely replace it with a lithium battery after my warranty expires. Until then, as long as they last at least a year, Tesla can't just replace them each year at the annual inspection. I imagine they check the health of that battery as part of the inspection.

Hopefully this issue will be designed out in the future cars like I have been hearing.
I'm very curious to see if the 3 will have the 12v battery. If they can do away with them without too much extra expense then they'll come out ahead as these 12v batteries have to be costing Tesla a bit to replace so frequently.
 
I'm very curious to see if the 3 will have the 12v battery. If they can do away with them without too much extra expense then they'll come out ahead as these 12v batteries have to be costing Tesla a bit to replace so frequently.

So, there is historical data that would suggest the 12V aren't going anywhere... The original 1.0/1.5 design of the Roadster, it has no 12V battery, the 12V was supported by the battery pack. The problems with that approach that were designed out of the system for Roadster 2.0/2.5 (added 12V battery) are;

1. What happens when vehicle is left with a low charge for an extended period of time? (the 12V drain could take it down to death of the pack and you can't charge the car if there is no 12V support due to the charging circuitry relying on 12V to stay "active" and ready to charge)
2. Keeping the DC/DC converter in the "always on" state makes the component more likely to fail and it is a very expensive component vs the 12V battery.

I'm sure they had their reasons and perhaps my two explanations above are poppycock but the reality is they started life with vehicles that had no 12V battery and quickly added 12V batteries into the design...
 
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If you aren't already, Plug your car in everyday. That will charge the battery. If you dont have it plugged in I don't think it gets much love.. with always connected enabled that computer in the center console sucks down some juice off the tiny 12v and puts a hurting on it
 
I'm sure they had their reasons and perhaps my two explanations above are poppycock but the reality is they started life with vehicles that had no 12V battery and quickly added 12V batteries into the design...
*Having* a 12v battery isn't really the problem I guess. Perhaps they need to consider either A) a different battery chemistry or B) a larger battery. I wasn't aware of the issue until it happened to me but premature death of the 12v battery Tesla is using seems to be more common than it should be.

If you aren't already, Plug your car in everyday. That will charge the battery. If you dont have it plugged in I don't think it gets much love.. with always connected enabled that computer in the center console sucks down some juice off the tiny 12v and puts a hurting on it
My car is always plugged in when I'm at home and not driving. I've spent maybe a dozen or so days traveling where it hasn't been plugged in overnight. I also have always connected off. My car is always asleep unless it's phoning home. So, in my case at least, it seems the battery just died prematurely.