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12V Battery Just Died - Total battery failure
- Thread starter skraack
- Start date
lUtriaNt
Member
what i did when i got my 3 in march was to get the ohmu battery and kept the conventional tesla battery as a spare.
destructure00
Active Member
If you all get extra batteries, keep them on a tender. Otherwise they will discharge, and if left that way for awhile, will be scrap metal when you need them.
DeanP
Member
Just had a chance to weigh my dead AGM out of Telsa. Came back at 30 lbs. 19 lbs saved. But sound system enhancement and hopefully more longevity is real reason I replaced with Ohmmu. Installed for 3 weeks now with impressive performance.
Also I talked to a Tesla Service Rep today about replacing my broken battery. Since I took it out of the car, they will not warranty replace the battery. They will recycle it for me, though. I may ask again next time I am in since when I went to request a service appt via app they quoted 3 weeks to replace battery. I ordered Ohmmu cross country and installed in 5 days.
So I guess in retrospect the thing to do is get them to replace it under warranty...then pull the replacement out as a backup and throw the Ohmmu in. On another note.....has anyone gotten a Mobile Ranger to replace the OEM battery quickly or quicker than a SC? I’m sure they ‘May’ have a few in stock a Ranger can install sooner? (I know wishful thinking)!
Ski
DeanP
Member
This probably has a lot to do where you're at. I was quoted 3 weeks to replace mine. They were scheduled to come out on 7/30 but asked if they would come sooner. They bumped me up and they (mobile unit) were here yesterday (week sooner). 3 weeks without a car is too long. 2 was hard enough. Great to be back in business. They replaced it under warranty with the same exact battery. Mobile guy said they last between 2-5 years. I got 2.
The lithium battery doesnt charge below zero, the temperature needs to be raised and there is no heating element in the battery.
As long as you are not in freezing weather and you didnt park it for a long time you will be fine with lithium battery. Basically you will create a chicken and the egg scenario for charging that battery when it gets too low in low temps.
As long as you are not in freezing weather and you didnt park it for a long time you will be fine with lithium battery. Basically you will create a chicken and the egg scenario for charging that battery when it gets too low in low temps.
grovny
Member
I had Tesla Mobile Service replace mine in my garage. Unfortunately I had to pay $129 (~ 56k miles on the car, close to 2 years old). I had them do it because I had to travel and needed it done when I got back. The guy told my wife that Tesla discourages owners from doing it themselves because of having to disconnect a hi-power line (?)
DeanP
Member
I watched the service guy swap out batteries. Let's just say, so simple a caveman could do it. Honest!
Just had to replace my 2018 RWD battery after it died as well. They disconnect the high voltage from a connection under the backseat.
DeanP
Member
Didn't even do that. Pulled off the Pos first! Everything else says Neg first. Oh well, it all works.
Should disconnect 12V at penthouse under rear seat, then swap 12V battery as normal, then reconnect 12V under seat. This prevent any chance of the penthouse/HV battery connecting the DC/DC converter when the positive cable is dangling and potentially touching ground...but what do I know....
My battery semi died overnight. The car seemed to have opened the rear, driver side window about halfway. With the amount of rain we get here luckily my car was in the garage.
The car was not waking up (screen dark) and opening the driver door from outside did not lower the window. The mirrors did not unfold. Interior lights were on. Plugged in (was 77% charged so did not plug in last night) and after ~1h went to check and when opened the doors the screen showed Tesla logo and booted
Why did you have to pay? Was it not covered under warranty for you?
The car was not waking up (screen dark) and opening the driver door from outside did not lower the window. The mirrors did not unfold. Interior lights were on. Plugged in (was 77% charged so did not plug in last night) and after ~1h went to check and when opened the doors the screen showed Tesla logo and booted
Why did you have to pay? Was it not covered under warranty for you?
My 2018 Model 3 LR with 10k miles just had a 12v battery failure and it had to be towed to Tesla. It was so dead that Tesla couldn't confirm the issue remotely and therefore could not dispatch the mobile service vehicle. The car was parked in the driveway so the tow truck operator had get it in towing mode by attaching a battery device to wires behind the tow hook cover then opening the frunk to get his battery attached to the car battery. It worked for awhile but eventually towing mode stopped right at the flatbed ramp. So we attached my 12 amp battery charger to the car battery but that didn't work either so he dragged the car the rest of the way onto the flatbed with the help of liquid dish washing soap. Oh, then the right hand front window went down so we had to cover it with a trash bag using 200 mph racer tape I had on hand. (I used to race cars) I needed to do this because I live in Florida and we have showers this time of the year. The car was getting towed to Tesla's new service center in Fort Myers which is only 30 miles away. Otherwise it would have to go 105 miles to the east coast or the the same distance to Sarasota. What a pain the rear end. I have a 2017 Model S 100D with 12k miles and I'm wondering if I should change the 12v battery to be safe. Any thoughts please.
If my 12V AGM battery failed, I would do the following. Open the frunk using the 9V battery I carry in my pocket anytime I drive my M3. Note, the frunk will not open if the 12V battery has not failed (new security feature recently added). Using the 10MM wrench I leave in my frunk remove the negative terminal from the 12V battery post, this essentially removes the 12V battery. Connect a portable jumpstarter to the positive post on the 12V battery and the removed negative cable (NOT the negative post). Leave the jumpstarter attached until you hear the contactors close and for additional 10 seconds to allow the 12V DC-to-DC converter to activate which is required to keep the contactors closed. At this point, the car should fully wake up and operator normally. Note, I have not tried using another car to jump start using this procedure. If you jumped from another car, make sure the engine is not running. At this point you will see an error on the center display indicating the 12V battery has a problem which it does because the negative side is disconnected. Even though the 12V is not connected the car is fully functional and and can be driven. If the tow truck has ramps, the car could be driven onto the tow truck (no need for tow mode which disables after 20 minutes) or driven to the SC for service.. If the car goes to sleep with the negative cable disconnected, you would need to repeat the steps as described above. I like disconnecting the 12V battery because it could have shorted cell(s) which could impede jumping in parallel or cause the car to sense a problem and shut down the 12V DC-to-DC converter which would disable the car. All of the above assumes that ONLY the 12V AGM battery has failed in some way it does not account for other possible problems (ie.. failed DC-to-DC converter etc....).
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Enginerd
Member
This looks like a great procedure, and I have no reason to doubt it. But how much of this is theory, and how much have you actually attempted (or can otherwise confirm)? The tea leaves say this is something I'll probably need to do in the next year or two.
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I edited my post please see changes. I have actually tested this procedure using a jumpstarter worked great. I hike in the middle of nowhere sometimes (no cell service) and would not like being stranded because of a failed 12V battery. Calling Tesla Roadside would many times not be an option for me.
Great info, but carrying around a 9V in your pocket all the time seems excessive! I wonder if there's some other way that's more convenient. Could a 3V button battery tucked into the back of an iPhone case work? Hmmm... how about stowing a 9V battery in one of those magnetic car key things we used to put in our wheel wells?
X Fan
Active Member
Good week for Ft. Myers towing...my X just died in the garage and needed to be towed late today...quite a process and it took a while for the operator to be able to get the X in tow mode. Then, I had to hard turn the vehicle to get it in position in the driveway to attach to his truck (the hardest part).
This is the second 12V that had to be changed in 2 1/2 years for this X and it came just after a SW update. The previous time I got a message and had about a month to get the battery changed...this one just died, a SW fail.
Oh well.....
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