Anybody have their 12v battery exchanged recently?

Anybody have their 12v battery exchanged recently?

Got an email from Tesla service yesterday morning saying my 12v battery needed to be replaced. I called Syosset minutes later. An hour and a half later the ranger showed up at my house and installed the new battery in the garage. My first experience with service as the car has only 3500 miles. Excellent service and very professional. By the way, I had no idea there was anything wrong with the battery.

J.T. | February 18, 2014

Had mine replaced last week when I brought my car to Syosset, Long Island for a stuck Charge Port door. They replaced the charge port and then told me they needed to replace the battery.

Jgrogan | February 18, 2014

I got the same email. Going in for annual service and a new battery

Velo1 | February 18, 2014

Yep, 3 times in 13 months.

SCCRENDO | February 18, 2014

2nd service 24000 miles. No known issue with my battery but they changed it out at my 2 nd service.

noel.smyth | February 18, 2014

24k miles as well, they also swapped it out. this will be my third one.

Eletrek | February 18, 2014

Received email last week and I had not had any problems. So they picked up MS85 Fri morning replaced 12v, did a couple of service bulletin updates, firmware update and returned call Fri afternoon. Also my 3rd 12v battery.

jordanrichard | February 18, 2014

Didn't Tesla fix this issue via a new battery supplier? What exactly is the issue?

Ralf_Kruse | February 18, 2014

Hello you.. i am here in Germany..

one of the proud first 500 owners in Europe..

have a red 12V Battery in my (also red) Tesla S.

do you have the same colour ?

whats wrong with that battery ?

i plan to install a little solar panel to avoid
battery getting broken..

tezco | February 18, 2014

The red battery is supposed to handle deep cycles better. Before sleep mode worked, the 12V worked overtime since it kept the computers going 24/7.

DTsea | February 18, 2014

had mine replaced last year at annual service. Seems to reduce drain while in sleep mode.

DTsea | February 18, 2014

last week at my first year annual service, I meant.

reitmanr | February 18, 2014

Not sure how they determine to swap a battery, but mine was also done at 1 year 12000 mile service. Vin 2859. I haven't heard that later battery lots had any problem. Car runs great with nearly zero problems. Service is better than any I have ever had! Enjoy!

JPPTM | February 18, 2014

FWIW, I have 9 months and 11,500 miles on my S85 from a May 2013 delivery--original 12v battery. Have a routine 12k service scheduled in a month--assume that I will get a 12v battery swap.

sosmerc | February 18, 2014

Are all these battery swaps free of charge?

J.T. | February 18, 2014


jordanrichard | February 18, 2014

Free of charge, but for how long? If there is an inherent problem with the batteries are we expected to pay for them once we hit 4 yrs/50,000 miles? If a "normal" battery in an ICE can go 5 years, running all of the electronics in the car, then what is wrong with these 12V batteries that runs just the non powertrain electronics, that the car is eating them up? | February 18, 2014

The story on the early 12V batteries is Tesla purchased them from an American company, who then sourced them from China, who then sourced them from Vietnam. The batteries were not the quality that Tesla had purchased and they were failing at an usually high rate (maybe 1-2%)?

Tesla replaced these batteries. Perhaps the replacement batteries also were not as good as Tesla wanted, and while not failing, Tesla seems to be going through the fleet and replacing them with a newer design when cars come in for the annual.

I don't think there is any issue with the electronics, but they do charge and discharge differently than an ICE car. The battery is different than ICE car batteries. It is a sealed gel-seal, a design that has proven very reliable (when the battery is good).

jordanrichard | February 18, 2014

Is there any indication as to when they started putting better batteries in the cars on the assembly line? My car is due to be built in 3 weeks. | February 18, 2014

Sorry, no idea. My car is 13 months old and they replaced it at the annual. I expect new cars are all getting the latest battery for some time. It would be quite costly for Tesla otherwise!

J.T. | February 18, 2014

Uh-oh. 3 weeks, Jordan? That means your car will be coming off the line in the last week of the first quarter; that could be a problem. The last week of the quarter last year is when they decided to dump all the A batteries into the production line even though Bs had been installed for months. Also, the gasket guy usually takes off in March to visit his ailing grandmother in Belgium and he's replaced by the guy who sweeps up. Get ready for some wind noise. You know the old saying March comes in like a lion and out like a Tesla with a poorly fit panoramic roof.

Maybe it'll all be good, though. Still, better to hope for the best and plan for the worst. :-)

jordanrichard | February 18, 2014

Ha-ha. My car is due to be built the week of Mar 10th and will get here (CT) presumably on the 26th. My DS gave me a choice of dates for delivery of 27, 28, or 29.

I plan on going over the car with a fine toothed comb and take it for a drive, to check for any air leaks form the roof and that missing gasket from the Belgian ( :-) )before signing anything.

sbeggs | February 18, 2014

@jordanrichard, are you sure they will "let" you take it out for a test drive before handing over your check/signing anything????

jordanrichard | February 18, 2014

No, I don't expect that they would let me drive off on my own, but perhaps my DS could ride shotgun. I just don't want to sign paperwork, drive off, and discover there is an issue with the alignment, wheel vibration, roof air leak etc. Sure they could fix it after the fact, but that's not the point. The DS or at least who ever preps the car for delivery should do a last minute quality check before delivery. There have been a couple of reoccurring things I have found on the various cars I have test driven that should have been caught before being put into service.

So I will be on the look out for those and insist they be corrected before they get my check. Business is business.

jomorale | February 18, 2014

My 2 cents...Tesla should just make their own 12V battery .

Pungoteague_Dave | February 18, 2014

It is more than just the battery quality that has been at issue. Tesla changed the battery technology completely, converting the early cars from standard 12 volt to a deep cycle AGM battery. It requires a wiring harness and firmware update. I have had two 12 volt batteries so far, with the conversion kit being applied when the first was replaced sometime last summer.

sosmerc | February 19, 2014

Seems somewhat odd to me, that with so much battery power available, that an additional 12V battery would even be needed.

hademarco | February 19, 2014

I had mine replaced in January. Had the car for a year and my annual service was not quite up yet. Got the email about the 12v, so I went in to have it done before my first trip to Vegas. Wanted to make sure the car was in tip top shape before the road trip.

NKYTA | February 19, 2014

Similar to @PD, I did not have the early lemon 12V and mine was swapped out for the deep cycle 12V at annual service.

Joseph4 | February 19, 2014

Got mine switched out at only 4,000 miles. My service rep implied that they are not really certain that they will have a permanent fix for the issue.

Captain_Zap | February 19, 2014


Yes. They are still working on optimizing the charging strategy for the 12v and working on finding the best battery for the task.

I think that there is some side effects from some changes they made quite some time ago to the relationship between the big battery and the small 12v battery. IIRC, at first, the big battery charged the 12v. To help range and sleep they changed it so that it is charged via shore power whenever it was plugged in.

I just try to think of it as all in the name of research. I wouldn't be surprised if they are tracking a bunch of different types of batteries in all of the cars in the field to see which battery types and charging methods work the best.

Meanwhile, if your 12v gets cycled a certain number of times, Tesla will notify you and replace it, just to be safe. It will also let Tesla know when the battery starts to appear weak so that it will be replaced preemptively. If you get a 12v low battery and Tesla hasn't contacted you for some reason, give them a call. One time I got a phone call and the other time I got an e-mail.

I am on battery #3. Battery #2 had the shortest life so far. It was put in after we changed to charging the battery via shore power.

Brian H | February 19, 2014

Stepping down high voltage to handle each of the 12V needs of the car is far harder than keeping a 12V battery recharged as needed.

Pungoteague_Dave | February 20, 2014

Pretty amazing that we seem to just accept that the 12 volt battery is a maintenance item, to be replaced already two or three times in the first year of ownership. I have never previously had to replace a battery in a modern car. Motorcycles and boats have been another story due to long periods of disuse. The Edmunds 12-volt battery shut-down story is more than scary. Too much of this and it will starting putting people off. Tesla needs a fix, and soon.

NKYTA | February 20, 2014

I have to agree with the Captain, Tesla is going through a bit of a learning process - the 12V battery was probably one of the few off-the-shelf parts of the car and has worked so well previously, so perhaps the testing wasn't as rigorous. Moving from the old 12V to the deep-cycle feels more like a design change, rather than a maintenance issue, but that's probably just mincing words.

My '98 Jetta was a workhorse and rarely needed maintenance, however in 15 years I went through seven 12V batteries, so something was clearly off in the electrical system.

sagebrushnw | February 20, 2014

An aside…the 12 Volt battery should be lasting a lot longer. My wife’s 2002 Subaru Outback wagon has over 100k miles and the original battery…146 months (12 yr 2 mo).

Captain_Zap | February 20, 2014


Did your wife's Subaru have a motorcycle battery too? ;-)

sagebrushnw | February 20, 2014

@ Captain_Zap

Just the OEM battery that came in the car.

Brian H | February 21, 2014

Reminds me of a Civic adventure I had many years ago. My (used) Civic kept losing electrical bits like turn signals, radio, etc. My regular mechanic spent 6 hrs trying to troubleshoot it, ended up giving up and replacing the master fuse for $1 (and refusing to accept $ for his time because he'd failed to solve the problem*) and sending me to an auto electric specialist. He found the car was actually a rebuild, and they'd put in a 90A Toyota alternator instead of the standard 60A Honda, and the accessories couldn't handle the power! When fitted with the right-sized generator, all was well.

*Ken Cho, Samson Motors, Vancouver BC, still in business AFAIK, and I've sent many to him over the years.

PBEndo | February 21, 2014

Mine is getting a new 12V battery right now. I took it in for some other problems and they informed me that the 12V battery was due to be replaced.

sosmerc | February 21, 2014

This issue clearly needs serious attention from Tesla. If we are to be dependent upon a conventional 12V battery, then I would like to have easy access to it so that I can change it myself. It should be no more difficult than changing out a battery in most ICE cars and trucks.
I am in the marine service industry and deal almost everyday with 12V batteries of different types. Proper charging will prolong battery life and I would be disappointed if I couldn't get at least 2-3 years of trouble-free service from a quality brand battery. Even with some abuse, I have customers that are getting over 5 years of service out of their batteries.

Captain_Zap | February 22, 2014

Does anyone know if the climate control runs off the 12v? If so, we have been using it a lot. | February 22, 2014

Climate control electronics and fans are off the 12v, but the heat-pump compressor is run off of high-voltage, due to the high power requirements. I doubt using the climate control a lot would affect the battery life.

Captain_Zap | February 22, 2014

I understood that the heat was radiant, and the heat pump was for cooling. I was taking the radiant heat literally... like with electric elements. The main battery does lose range when it the heat is running but the AC seems to consume even more juice.

I guess the real question is what accessories run off the DC-DC converter and what runs off the 12v and what changes have been made.

I'm on to another theory that I have to ponder a bit.

I just realized that my BMW had two huge batteries. I always wondered why. The Tesla battery looks like a smaller battery to me. Maybe they can add another battery near by in that big empty space behind the frunk.

vickieschmidt | February 22, 2014

Work order said: "Replaced 12v Exide with C&D Battery and coded vehicle for new battery"

Captain_Zap | February 22, 2014

It sounds like they are on top of it.

SMinnihan | February 22, 2014

whatever you do, don't call it a recall.....

Mathew98 | February 22, 2014

Dang it. Shorties got toasted over the last few weeks and now have to work OT in the weekend. How's that minimum wage working out for ya???

Yo Obama, you must raise the minimum wage to $1000/hr for these schmucks. Idiots have to make a living too! | February 23, 2014

@Captain_Zap - Sorry, my answer was not complete. There is a resistive heater as well as the heat pump. The heat-pump allows both heating and cooling by changing the direction of the pump. For most heating, it is 2-3 times more energy efficient than a resistive heater, and is the preferred way to heat the cabin.

As the temperatures get lower, the efficiency of the heat pump goes down, so that at about 0 degrees F, it has the same efficiency as a resistive heater. At that point it is better to just use the resistive heater. I.m sure Tesla's software controls the HVAC system to maximize the efficiency.

Other EVs in the past have not used a heat-pump design, and is one of the reasons they had a dismal cold weather range.

models60 | February 23, 2014

Took the car for 12,500 mile service, they replaced the 12v battery. Didn't have any issues with original 12v battery.