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12 Volt Battery
- Thread starter Peg_
- Start date
Remember the original Roadster didn't have a 12V battery and they added one back. The "accepted" reason is there are safety and regulatory concerns that the airbags, hazards, and brake lights need to keep working after the HV battery fuse explodes during a crash. My guess is if they did remove the 12V battery, they would replace it with something else like super capacitors.
My guess is never (which is a very long time). It's the only battery tech that works at -40C.
Tesla just needs to maintain it better. I think they try to use the HV pack as little as possible and that inadvertently kills the 12V battery by deep cycling it. They just need to manage it better and it's not a priority.
Tesla just needs to maintain it better. I think they try to use the HV pack as little as possible and that inadvertently kills the 12V battery by deep cycling it. They just need to manage it better and it's not a priority.
Being stranded is never a good thing. I know there were some issues on the M3 12 volt. Are there any maintenance habits that can help prolong the life of the 12 volt battery? And does anyone know the approximate time to failure? We usually replace our vehicle batteries at 5 years to avoid having issues. Realize we may be replacing a perfectly good battery, but it is a minimal cost and helps prevent being stranded. Wonder what the generally safe time range is for the MY? Maybe 2 years?
I heard the 12 volt doesn’t last long, possibly 1 to 3 years....would be a pain to have to replace them so often.....Techs take 25 minutes plus $$ to replace it....you can DIY but it’s a pain to reach it and it takes you longer. You get a warning when they (12 volt) are close to failing but still must be dealt with. Without the 12 volt, the items that it powers would be using the main battery....and the main battery life is getting longer and better......without the 12 volt you might end up with a tad bit more room in the frunk...not much, but some.
One of the suggestions I read to prolong the life of the 12 volt is to turn off the mobile app. That would not be fun for me as I like all my techy gadgets working all the time....lol
I'll really have to disagree here. It's under a pop off panel (3 seconds), a pop off air director (another 3 seconds), then it's three bolts and one vent tube away from coming out. It will literally take longer to drive to get the battery than to change it. Heck, AutoZone and Discount will (likely) change it for you if you want.
Tesla has promised more 12V battery oversight so hopefully the amount of people getting stranded will drop but when it does it's really not the end of the world.
I watched a guy on you tube trying to “pop off” the pop off and he struggled with it. He finally had to jam a “covered with electrical tape” screwdriver into the side to get it open. Kinda chancy....I personally wouldn’t to it....but to each his own. Still a pain with having to replace the batteries so often.....and getting stranded just once is once too many (for me, anyway, lol). Just my personal opinion....others may feel differently about it all.
I think a 12V battery is required by DOT so any change will be relatively far in the future.
The 12V battery powers everything (UI, entertainment, blinkers, etc.) when the main battery that powers the drive is off.
In the case of a bad accident, the main battery is disconnected (blow fuses or physical connections) so the car needs the 12V battery.
I plan to replace my factory 12V with an OHMMU lithium in about 2 years. I think Maxwell (Tesla bought them) had supercap-based car batteries which were impressive. A Tesla doesn't need massive cranking current for it's 12V battery so the tech isn't the best fit, but they might be doing something to remedy this issue.
The 12V battery powers everything (UI, entertainment, blinkers, etc.) when the main battery that powers the drive is off.
In the case of a bad accident, the main battery is disconnected (blow fuses or physical connections) so the car needs the 12V battery.
I plan to replace my factory 12V with an OHMMU lithium in about 2 years. I think Maxwell (Tesla bought them) had supercap-based car batteries which were impressive. A Tesla doesn't need massive cranking current for it's 12V battery so the tech isn't the best fit, but they might be doing something to remedy this issue.
Agreed. I've replaced the 12V battery mutliple times in old ICE vehicles--it's simple.
Having AAA or a cheap jumper kit will probably alleviate any concerns of being stranded due to a dead battery.
Having AAA or a cheap jumper kit will probably alleviate any concerns of being stranded due to a dead battery.
Perhaps you can use one of those Li-Ion battery boost/jumpers in a pinch, to supply 12V and get you out of a bad spot? The one I have for my ICE is pretty small and good for up to 600 CCA, and it can boost many times before needing to be recharged. Might be a viable backup option... Always thought it was amazing how something so small has enough energy to jump start a car. Makes you wonder just how much energy is in the battery pack in our Teslas...
alexcue
Member
Well this is good to know. I have one of the Noco Boost's I keep one at office and home. Saved my boss once or twice, so it was worth it. Never thought I would need it for my MY! Guess if I'm going somewhere, I'll just throw it in the frunk, the case is tiny and have it for peace of mind.
Replace 12V every two years. Or replace at two years with the lithium replacement battery (forgetting the brand).
Not a biggie for expense or effort. Anyone balking at this sort of expense shouldn't be buying a $50K vehicle. And as others have pointed out, a separate battery is necessary to isolate the monster 400V main battery so it doesn't kill everyone in the vicinity of a damaged EV.
I used to replace 12v ICE batteries every 3 years. My mechanic thought that was weird. What I think is weird is having a dead battery at the mall on Christmas Eve during record cold temperatures.
Not a biggie for expense or effort. Anyone balking at this sort of expense shouldn't be buying a $50K vehicle. And as others have pointed out, a separate battery is necessary to isolate the monster 400V main battery so it doesn't kill everyone in the vicinity of a damaged EV.
I used to replace 12v ICE batteries every 3 years. My mechanic thought that was weird. What I think is weird is having a dead battery at the mall on Christmas Eve during record cold temperatures.
FYI, here’s some good information I just found. The more we know, the better.
12 Volt Battery Compendium – TeslaTap
12 Volt Battery Compendium – TeslaTap
And your use case may help explain why you never had any 12V issues. I suspect 12V issues are related to how long the car sits idle, and asleep. With 250K+ miles, your vehicles have not been idle very often, so your 12V has always been topped off via the HV main battery I suspect. And those vehicles that spend most of their time parked, may not sufficiently keep the 12V charged up to help against vampire losses. Elon mentioned something about this and a change to address the 12V issue, which I interpret as a software change to awaken more often and service the 12V to prevent it from draining too much when parked. No idea, just a guess. So the main HV will take a small hit/loss to make sure the 12V is properly charged to prevent replacement every 2 years. ???
