Near annual replacement of 12V battery is typical according to Tesla Service Tech

[sorka]

When I'm at work, I use UMC to charge the car off 120v outlet... which is enough to close the contactors (obviously) and fire up the Dc-to-Dc converter in the car.. which powers the 12v circuits keeping the load off the 12v battery as well so it doesn't cycle during the day. It also pays for my commute energy. That's another 8 hours of every day of no cycling.

I'm unclear how this helps. Even if you leave the UMC plugged in it will not draw power until the 12v battery draws down to about 50% of SOC. The 12v battery has between a 60 and 70 watt continuous load. When it draws down far enough, the contactors close and the main either the main battery charges the 12v battery or shore power charges it.

In either case, while the contactors are closed, there's a continuous load on the 12v battery drawing it down.

When the 12v battery is new enough and not degraded, this happens about 6 times a day. As it degrades, the cycles speed up because SOC draws down faster.

 

[sorka]

My 12v battery was replaced under warranty at 14 months and 21K miles.

Manufacturers typically have a 12 month free replacement period prorated after that, so I was surprised Tesla did it under warranty.

I'm pre refresh so it's only about 10 minutes to pull the battery out.

 

[tga]

I did. They said they tag-teamed it and I believed them. Lawrence has changed their service model since I was there last and it was all-hands-on-deck.

But why wasn't it covered under warranty?

I'm unclear how this helps. Even if you leave the UMC plugged in it will not draw power until the 12v battery draws down to about 50% of SOC. The 12v battery has between a 60 and 70 watt continuous load. When it draws down far enough, the contactors close and the main either the main battery charges the 12v battery or shore power charges it.

In either case, while the contactors are closed, there's a continuous load on the 12v battery drawing it down.

When the 12v battery is new enough and not degraded, this happens about 6 times a day. As it degrades, the cycles speed up because SOC draws down faster.

If the car is charging, the HV bus is energized. If the HV bus is energized, the DC-DC converter is active, so no 12V cycling.

 

[sorka]

But why wasn't it covered under warranty?


If the car is charging, the HV bus is energized. If the HV bus is energized, the DC-DC converter is active, so no 12V cycling.

Sure, if it's constantly charging. I guess at 1.3 KW it would probably be charing all day long

 

[tga]

Sure, if it's constantly charging. I guess at 1.3 KW it would probably be charing all day long

Yeah, "slow 120V charging == all day charging" was my assumption, too.

 

[Evoforce]

I replaced mine with a lithium battery. Ordered it from Battmobile.( I think that is how it's spelt.) They have a video!

 

[FlatSix911]

I replaced mine with a lithium battery. Ordered it from Battmobile.( I think that is how it's spelt.) They have a video!

Can you share more details on the product and the installation process?

 

[Evoforce]

On eBay, search Tesla lithium battery... They also provide installation video.

 

[Falkirk]

I know this is the Model S thread but I really hope the 3 has been designed to be maintained easily. I worry all $500 battery replacements compared to any car I've ever owned, that's a very big difference.

 

[CalBlue 85D]

I know this is the Model S thread but I really hope the 3 has been designed to be maintained easily. I worry all $500 battery replacements compared to any car I've ever owned, that's a very big difference.

Welcome to the world of Tesla......

 

[zwede]

I know this is the Model S thread but I really hope the 3 has been designed to be maintained easily. I worry all $500 battery replacements compared to any car I've ever owned, that's a very big difference.

Remember that most that post are the ones that had problems. I've had my MS for 4 years. The SC replaced the 12V for free after 2 years even though I never had any problems with it and had no warnings/error messages. After that I got a CTEK battery tender which I hook up whenever the car is home and I don't expect any 12V issues anytime soon.

 

[Cyclone]

I'm still using a C-tek smart charger on the car every night while parked in my garage, to keep the 12v recharge cycles off for about 1/3 to 1/2 of every day.

When I'm at work, I use UMC to charge the car off 120v outlet... which is enough to close the contactors (obviously) and fire up the Dc-to-Dc converter in the car.. which powers the 12v circuits keeping the load off the 12v battery as well so it doesn't cycle during the day. It also pays for my commute energy. That's another 8 hours of every day of no cycling.

It also doesn't cycle when you're driving for the same reason. So all the commute time, another hour of the day no cycling.

No 12v replacement yet on a September 2014 delivered car.

I was "expecting" near annual replacement of this part when I bought the car. Now I've reset my expectations to "maybe every 5 years" and wouldn't be totally surprised if I got 10 years out of it if I keep up the current practices.

FYI the C-tek was on the order of $200 ... so good investment.

I live in a "cold" climate which is also friendlier on lead/acid batteries. Arizona type heat is hard on them. So your mileage may vary.

My early 2013 w/ 63k mile S 85 had it's battery replaced in 2014 at the one year mark and not since. I take zero special actions around maintaining the battery. So definitely YMMV.

 

[mknox]

My early 2013 w/ 63k mile S 85 had it's battery replaced in 2014 at the one year mark and not since. I take zero special actions around maintaining the battery. So definitely YMMV.

My February 2013 build S85 has about 86,000 miles on it. I've had at least 2, maybe 3 12v batteries over the years. The last one was less than a year ago, and Tesla Service (Mississauga) replaced it for free while I waited.

Interestingly, I have a 10 year old Pontiac Vibe with about 116,000 miles and it is still on it's original factory 12v battery. I think this must be some sort of record.

 

[asim120]

My February 2013 build S85 has about 86,000 miles on it. I've had at least 2, maybe 3 12v batteries over the years. The last one was less than a year ago, and Tesla Service (Mississauga) replaced it for free while I waited.

Interestingly, I have a 10 year old Pontiac Vibe with about 116,000 miles and it is still on it's original factory 12v battery. I think this must be some sort of record.

That's funny. My second car is a 12 year old Pontiac Vibe with 130,000 miles and it has had as many 12v battery replacements as my 2014 S 60: one.

 

[muleferg]

My Model S 2014 12v Bat lasted 2yr 9 mo.

 

[tga]

That's funny. My second car is a 12 year old Pontiac Vibe with 130,000 miles and it has had as many 12v battery replacements as my 2014 S 60: one.

I've heard several anecdotes about GM batteries lasting a long time. We got 10 years on the original battery in a 2000 Saturn.

 

[rypalmer]

13 month old Model S (refreshed nose), 44,000km, 12v battery warning presented 1 month after the annual service visit. Took the car in last Thursday and they replaced it very quickly, in under 45 minutes. The labour charge was 1.5hrs @ $150 though :| Battery $206, labour $225, total $487.03 CAD.

Little update.. Tesla contacted me and refunded the full amount. They said I was charged in error, but didn't elaborate.

 

[JRP3]

Glad to hear it, they did the right thing.

 

[mknox]

That's funny. My second car is a 12 year old Pontiac Vibe with 130,000 miles and it has had as many 12v battery replacements as my 2014 S 60: one.

Just like me, you have two cars that came out of the same factory! (FYI: Pontiac Vibes were made in Fremont when that was the NUMMI plant).

 

[fcharland]

Just came back from the SvC, and looks like there is a 3rd gen 12V battery! Now says DCS "+" on the sticker. See my "old" battery pictured in the background.

Wonder what have been improved...