Like many aspects of these cars with OTA software updates, it is very difficult for us as owners/users to know where the inconsistencies and problems lie. In both our cases, we've have 12V batteries last 3+ years and yet we've also had batteries trigger the replacement warning around the 1 year mark. I'm not sure if the 12V batteries themselves are no reliable, if it's the draining/overcharging of the 12V battery, or some software glitch that is impacting the battery life. We all recall the eMMC issues on the MCU1 after various software updates. Whatever the problem is I hope they fix it fast.
-
Want to remove ads? Register an account and login to see fewer ads, and become a Supporting Member to remove almost all ads.
12v Battery life
- Thread starter Bigswing
- Start date
Just changed mine original battery also, 6 years to the month. Though mine is a late 2016, was a showroom demo car with 400 miles when I bought it, so battery was actually more like 6.5 years old, as unlikely they changed it out before I bought it as first owner.
Mine started to get the "schedule service warning", I thought it was because I'd gone on a 10-day trip, and the HV battery had drained from 70% to below 20% near the end, so I thought maybe it stops recharging the 12V after the HV battery got below 20%. But I checked my Teslafi logs, and it looks like the car stopped sleeping normally about 2 days BEFORE I left on the trip. So it's really the other way around, the dying 12V battery causes the car to not sleep properly, and that increases the phantom drain while I was away. Saw a similar thing with a relative's Model 3, where it was the 12V that caused increased phantom drain along with other weird behaviors, and the 12V warning only shows up weeks later.
New 12V battery (AGM according to the invoice) was $165, plus $50 for labor via mobile service (slightly cheaper than some reported here for older Model S, maybe because easier access on my facelift model). As others stated, you schedule via the app for the service center, but then they reach out and change it to mobile service with usually an earlier date - in my case they scheduled the very next morning.... Also had the 12V replaced proactively on my 5-year old 2018 Model 3 on the same visit; comparatively, $85 for the (lead acid) battery and only $25 for labor, he swapped it so quickly I thought he was putting the new one back in the cardboard box he'd just took it out of. At these prices for OEM battery and mobile service, I'll never bother doing 12V replacement myself after 20+ years of DIY on all my previous cars.
I made my appointment yesterday to have the 12V battery replaced next week. Total was $285 for battery and labor on my 2013 S85.
Hi all, just changed mine this Tuesday. Unless Tesla changed it without my knowledge during base warranty, still had the original 12v (all red sides and top) on our nov 2013 build, so roughly 91/2 years and 291,000 km. I had bought, a replacement one (black sides/red top) from the Tesla parts department about 6 years back as "a just in case it fails" as I kept reading about people getting stranded because of 12v back then (we live far from a Service center). I kept it charged using a small photovoltaic 12v charger since then. Was not as bad as I thought it would be. Had to recharge it a bit on the low side (12.5). My timer on the Snap On charger failed me and it charged for about 2 hours (also it was very dark in the barn where the charger was and I sparked it a bit mixing poles while connecting) . When I installed it, after resting for about 1 hour, it was reading 13v.
As an aside, while being at it, I wanted to look at the ground points under the Frunk's tub and I have two bolt's at the bottom of the tub that stripped because of rust. I managed to get one out but have still one stuck and cannot manage to wiggle it out as it stripped lower that the other one under which I could put a large screwdriver. Any suggestions other that my idea of cutting the plastic around it ?
As an aside, while being at it, I wanted to look at the ground points under the Frunk's tub and I have two bolt's at the bottom of the tub that stripped because of rust. I managed to get one out but have still one stuck and cannot manage to wiggle it out as it stripped lower that the other one under which I could put a large screwdriver. Any suggestions other that my idea of cutting the plastic around it ?
Attachments
I'm sure it's at least that much for my 2013. It's really buried under everything and not easily accessible without disassembling a fair bit of stuff to get to it, and even then there's a lot of wiring that needs to be shoved out of the way. I was getting around 2 years of life out of the OEM AGM batteries. It's been two years with the Ohmmu and so far I've had zero issues. I was physically sore after removing the AGM battery since it was so awkward to reach. The much lighter Ohmmu battery was a welcome relief. If the battery were easy to replace I most likely wouldn't have bothered with the Ohmmu.
Correct, the location of the battery is poorly designed location for earlier releases of S, but I stand by my comment on my experience with Ohmmu, that is no support, no response. I understand they have tons of issues in 3/Y and I felt sorry for them, I can only empathize but that doesn't absolve my 400 dollars paper weight purchase.
Hugh Mannity
Mediocre Member
Is that the original battery ? Wow !! I thought I was doing well; I'm coming up on 7 years next month and still running the original. The longevity seems to be all over the map for some reason. Some get 12 months out of them and others like us go on for years and years.
I probably will recommend you replacing it to avoid the DC-DC fuse from being blown. The car will need to over-use the DC-DC converter to maintain the 12v battery. Hence, more DC-DC usage.
Unfortunately no it was not the original 12V battery. I bought the car used from Tesla back in December 2018 when the car had just under 60K miles. Tesla replaced the 12V battery when they were doing warranty work at 90K which included the drive unit, HV contactors, pyro fuse, HVAC drain hose, and TPMS retrofit (Continental). The replaced 12V battery lasted 20K miles/25 months before the 12V replacement warning popped up.
From what I've read, Tesla's 12V system is rather taxing on the low voltage battery and they still haven't come up with a good way to alleviate the stress. The mobile service tech said he does A LOT of 12V battery changes on Model S/X and believes the actual software updates (especially if the install gets hung up) and sentry mode are the major drains for the low voltage system. In comparison, our 2013 Fiat 500e has 10yr/84K miles and is still on the original Mopar 12V battery.
I am proactively replacing the OEM 12V battery next week on my Aug 2017 MS100D. Can't believe it has lasted this long. No 12V alerts or warnings. I just think it is time. Plus, winter will be here soon and it can't possibly make it through another cold winter (can it?)
Edit: 91,000 miles and lotsa long roadtrips.
Edit: 91,000 miles and lotsa long roadtrips.
NewbyMaybe
Newby1Kenowby
Do you drive your car regularly? I got the message when I wasn't driving for some days due to covid. I canceled the 12V error message with a trick, changing the tire configuration on the screen. I don't know if this will still cancel the error codes. I was driving for over two years until the error code come back due to the car stand still about 4 weeks at a SeC for a HV battery replacement.
I'd keep it as is. If you have no signs of trouble, why change it. Tesla's warnings are way ahead of failure so you will have plenty of time to change it yourself or have them do it whenever the car warns you about it. On your model year, it is very easy to change by yourself
I have no particular rhythm with this car. It can sit for a few days at a time several times a month, and then I'll drive 500 miles.
Because of Murphy's Law. It's living on borrowed time and will need to be replaced sooner rather than later. I choose sooner, and under my terms. I will see if they let me keep it and take an older battery I have for the core charge.
I had the same thought process (a least I think) and preemptively purchased one many years ahead of my S telling me it needed attention (I obviously kept it maintained). I waited more than a month to do the change after being alerted by the car and all was fine. My opinion only, whatever you decide is perfect with me, just sharing my experience.
I’ve had the ‘replace 12v battery’ warning on for 3 years and 50k miles and have just ignored it. I have a battery monitor attached and it never dips below 12v. Theres clearly nothing wrong with it. It started when I drained it inadvertently whilst being in the car stationary for a long period of time. I just charged it back up and all was good. But the warning continues to show. I have to reset it by doing the ‘wheel configuration’ change to get it to install a software update but it always comes back on after a few miles of driving.
I heard once that it triggers something in the battery once it goes flat the first time, and following that it will always show the warning even though there’s clearly nothing wrong with it.
I heard once that it triggers something in the battery once it goes flat the first time, and following that it will always show the warning even though there’s clearly nothing wrong with it.
There is no reset required when replacing a battery…. So maybe try disconnecting it and reconnecting it?
If it thinks the 12v is bad it is supposed to not let the car sleep.
I'm sure it was the Tesla Mobile technician who said something like 'if the plates inside the battery touch, the warning will always show even if the battery is charged back up again, there's no way to reset it other than replace the battery'.
I could be wrong, all I know is that the warning will never go away fully, despite me knowing 100% that the battery is perfectly ok
Similar threads
