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12v battery dead - need roadside assistance?

Hey guys!
My first post on a forum and already have a big problem :(
I have just received my Tesla Model 3 RWD version about 3-4 weeks ago, just before my long planned 3 weeks holidays in Okinawa. I drove it only for about 150km, tried out supercharger, calibrated the cameras and that's about it before I left for holidays. I left the car with about 250km of range and as much as I knew it might be a bit low I was fairly confident to leave it like that as I have a mobile connector and a plug in my house so I could charge it up before going to the supercharger or Chademo.
However, just after 5 days I received notification on my app that the car is shutting down due to very low charge and I already started getting worried (how can car on idle use 250km range in just 5 days?!). It got even worse when I got back home yesterday - the car has completely shat down and no mobile app nor key card lets me unlock it. What is worse my mobile charger is stored in the frunk so even if I could get to open the charging port I cannot get my mobile connector out.
I did some research and this morning went to YellowHat, and got myself a battery charger for the 12v hoping that the frunk will open when I just attach it to the the cables in front. However, not just it didnt pop the frunk but it also seems like the battery is not charging at all - after 2h being attached I still cannot open the doors.
Did anyone have similar problems? I sent enquiry to request for roadside assistance, but not sure how responsive they are over the weekend.
Also, do you think it will be covered under the warranty? I still feel like there might be 2 problems here. 1) Got to replace the 12v battery. 2) The main battery is using way too much energy on idle - 250km of range of the battery fresh out of the factory should be enough for a couple of weeks?

Thanks for the help.
Cheers!
 
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Tam

Well-Known Member
Nov 25, 2012
11,268
10,307
Visalia, CA
....covered under the warranty?...
Because you didn't follow the owners manual instructions to plug in as much as possible especially in your case, Tesla might charge you for the disobedience. It might be nice and cover the cost for you if it feels sorry for you.

To charge your 12V, you need to open up the frunk and the cover at the base of the windshield. You said the frunk didn't open so there's no way the 12V battery got recharged.

Tesla-Model-3-12V-Battery-Replacement-Service-CleanTechnica-Watermark-11-1536x1144.jpeg

Photo credit: CleanTechnica.com

Most likely, the sentry mode was on and that consumes lots of energy. If the temperature is too hot or too cold for your battery it can automatically turn on its HVAC and that also confirmed lots of energy.

Since you don't know how to open the frunk, it's time to call roadside assistance.

In conclusion, please start the habit of plug in your car even when you are at home so you won't forget to do that on vacation.
 
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Tam

Well-Known Member
Nov 25, 2012
11,268
10,307
Visalia, CA
...The main battery is using way too much energy on idle - 250km of range of the battery fresh out of the factory should be enough for a couple of weeks?...

When I don't shut off everything in my car like Sentry Mode, my vampire loss is significant: 28.65 miles per day or 1.19 Miles Per Hour =45.84 km/d or 1.91km/hour.

If I lose 45.84 km/d x 5 days = 229.2 km so no wonder your 250km range can barely cover that.

BxgMDhk.jpg


If I don't use Sentry Mode, the loss is less: 0.21 mph x 24 = 5.04 miles/day or .336km/h x 24h = 8km/day

Q4gWn48.jpg
 

ATPMSD

Active Member
Mar 12, 2021
1,435
1,365
Atlanta, GA
Fundamentals:

  1. When the car is asleep the 12v system remains active. As the 12v battery voltage drops the car will recharge it as needed using the HV battery. Your car will lose 0.5-1% / day from the main battery with Sentry off and about 5-6% / day with it on. If the HV battery gets too low the car will stop charging the 12v to protect the HV battery from fully discharging. Leave the car long enough and the 12v battery dies.
  2. If the battery is dead you cannot open the doors, frunk, etc. The cable in the front of the car is to operate the Frunk when the battery is dead, they will not charge the battery.
  3. You do not need to recharge or replace the battery. What you need to do is jump the battery by connecting directly too it (photo in post #2). You also need to get the HV car battery plugged into a charger! Once there is power supplied to the 12v battery it will close the HV relay and begin to charge the 12v battery. You can then remove the jumper.
 
Hey again! Thanks for all the answers, it's very educative. I should have researched more before leaving the car for so long. I was under impression that it's gonna be <1%/day 😭 So looking at the calculations it seems like even if it was charged to a 100% it would be a super tight call to survive 3 weeks on idle. What do most people do? Do you just leave it plugged in when going for a longer trip?

If the temperature is too hot or too cold for your battery it can automatically turn on its HVAC and that also confirmed lots
Yeah, the Tesla support guy suggested that it might've been the case as Tokyo had some pretty hot days over the last few weeks.

Since you don't know how to open the frunk, it's time to call roadside assistance.
I think I know how to do it following the Tesla manual and some YouTube videos. I tried to use the jumper to emergency open the frunk with the two cables in front as explained before. Also bought a 9v and 12v batteries and tried that today, but none of these 3 methods worked. I only hear a slight sound of the mechanism, but that's it (sort of like trying to open a closed doors). I suppose that would mean that the 12v battery is not fully discharged and the emergency frunk opening is not available.. though Im still not able to open the car with the card.
I called for the roadside assistance explaining what steps I took and they said they can come but will basically just repeat the steps I took. I scheduled them to come anyways as I ran out of ideas of how to get into the car. Also, it seems like the earliest they can come is Wednesday! Does anyone know of there's any way for more urgent response? Just worrying if I have to wait a couple of days if I ever get stranded somewhere 😅
 
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Tam

Well-Known Member
Nov 25, 2012
11,268
10,307
Visalia, CA
...Do you just leave it plugged in when going for a longer trip?...
Yes. If I have a choice, I would always plug it in. I only don't plugin because I can't such as driving...

This is a quote from the manual:

"About the High Voltage Battery​

Model 3 has one of the most sophisticated battery systems in the world. The most important way to preserve the high voltage Battery is to LEAVE YOUR VEHICLE PLUGGED IN when you are not using it. This is particularly important if you are not planning to drive Model 3 for several weeks."

The capitalized words are not from me. It's from the instruction.

Some people like to wait to charge but the manual instruction is against it:

"There is no advantage to waiting until the Battery’s level is low before charging. In fact, the Battery performs best when charged regularly."

---
If you can't plugin and want to conserve energy, these are things that I can think of:

1. Sentry Mode-Off
2. Summon Standby Mode-Off
3. Disable Mobile Access
4. Disable Data Upload (to Tesla)- click ""do not agree""
5. Climate Preconditioning - Off
6. Cabin Overheat Protection - Off
7. Make sure HVAC off when you leave-Disable ""Keep Climate On"".
8. Do not use Tesla App or any third party data-logging apps. These wakes up your car. You want your car to hibernate.
9. Scheduled departure-Off



I think I know how to do it following the Tesla manual and some YouTube videos. I tried to use the jumper to emergency open the frunk with the two cables in front as explained before. Also bought a 9v and 12v batteries and tried that today, but none of these 3 methods worked.
Can you connect the front bumper wires with a regular car jumper so that I can have confidence that it has enough energy?

91UOxZFYVGL._AC_SY879_.jpg



I only hear a slight sound of the mechanism, but that's it (sort of like trying to open a closed doors). I suppose that would mean that the 12v battery is not fully discharged and the emergency frunk opening is not available..
You do not need the Tesla car's 12V battery (full or empty, good or bad) in order to use the frunk emergency opening procedure with your external jump starter.

If you have a good source of 12V DC energy to inject to those 2 wired in the front bumper, you can open the frunk.

...though Im still not able to open the car with the card...
That is expected. Your 12V battery is dead. To read the card, your car needs to have a good 12V DC for the card reader.

...Also, it seems like the earliest they can come is Wednesday!...
That's not worthy of the name Roadside Assistance. That service should come immediately to you when your car is dead and your car is now.

I am sorry for the bad service.

Does anyone know of there's any way for more urgent response?
Tweet Elon Musk?
 
Hey @Tam, thanks a lot, really appreciate you taking time to respond! And thanks for providing the ways to conserve energy.. truth is I haven't done almost anything on that list before l leaving so definitely have just myself to blame for that 😅
In my case probably a bit difficult to leave it plugged in all the time as I don't have garage and just an outdoor parking spot in front of the house. I read that it's better not to leave it plugged in in the rain so just need to find some proper way to isolate it (or build a small roof ha).
You do not need the Tesla car's 12V battery (full or empty, good or bad) in order to use the frunk emergency opening procedure with your external jump starter.
So not sure if I'm reading it correctly, but actually from what I've seen in the Tesla manual it seems this method only works if the 12v is fully dead and there is really no other way to get the frunk to open? Model 3 Owner's Manual | Tesla

"The following steps do not open the front trunk if Model 3 is locked and has low voltage power."

Can you connect the front bumper wires with a regular car jumper so that I can have confidence that it has enough energy?
I'm attaching the photos. Not sure if this jump starter I got is the right tool for that tho.. seems like it's very "idiot-proof" and has only one button to change the modes. I suspect maybe it doesn't provide energy if it's not attached to sth that can actually charge? Also, tried with the 9v battery as I've seen this trick worked on YT, but all I got is the "ticking" wound on the front trunk (can't upload the video right now as it seems too large, bit will try to record just the sound later).

I'm hoping the guys coming on Wednesday will have better luck than me and that I don't actually have to hire a car Transporter to move it to the service 😭
 

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ATPMSD

Active Member
Mar 12, 2021
1,435
1,365
Atlanta, GA
only hear a slight sound of the mechanism, but that's it (sort of like trying to open a closed doors). I suppose that would mean that the 12v battery is not fully discharged and the emergency frunk opening is not available..
If there is sufficient voltage in the car's 12v battery the emergency frunk open will not work. BUT, since you are hearing a mechanical noise it may be working. Try this. First press down on the frunk to ensure it fully secured. Next, connect a 12v battey to the emergency leads at the bumper, after you hear the mechanical noise lift up on the frunk. Note the frunk does not "pop open" in the usual sense, or it may be sticking a bit. You may have too leave the 12v battery connected when you lift. If that does not work, disconnect the 12v battery and get someone to gently pull up on the frunk as you connect the 12v source.
 

hiroshiy

Active Member
Moderator
Apr 6, 2013
2,448
2,105
Tokyo, Japan
@itmightgetloud, welcome to the forum!

Tam wrote a good summary of what you should have done before leaving, but first, you need to open the frunk.
If you hear the noise when you connect 12V power, 12V is low but still alive, and since you locked the car, it doesn't allow you to open the frunk.

For non-Japanese helpers - this 12V equipment is not a simple jump starter.

I see you connected the 12V external power source, but it is set to 6A charging mode, reading from the indicators. That's only 12x6=96W, and it is not sufficient to hold the circuits to work. I don't know the idle power of Model 3, but my Model X usually consumes close to 500W in idle. Try Cell Start mode - click the switch twice to read indicators like this:
6A - flickering
4A - off
2A - off
0.8A - off
PROTECTION/ERROR - off
Snow - off
Normal - off
Cell Start - ON <<make sure this indicator is on

The above steps will give your car much higher power to work with your car's computer(s). Next, try unlocking the vehicle with your key card after connecting the 12V power source with cell start mode. Once unlocked, you can get into the car and see the main screen. Keep the power source connected until you open the charge port and connect the charging cable to the vehicle but not to the outlet. Then, disconnect the power source and plug the mobile connector to the outlet.

I hope this helps...
 
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Hey guys @ATPMSD and @hiroshiy thanks for the help!
So I tried both of the suggestions (pulling the frunk manually when attaching the power source and using the highest power on my jump starter), but it did not help. Finally, yesterday the road assistance arrived and had it fixed in just a few minutes 😅
Apparently, the power source I was using was way too weak to even open the frunk. My Japanese is not so great, but if I understood correctly, it seems like the 2022 model 3 might be using a slightly different 12V battery (or maybe just some of the cars?) and actually need a better power source to even open the frunk. The guy mentioned he has to go to clients with a similar issue at least once a week, so that makes me feel not so bad about myself anymore :D Gotta go shopping in Amazon to have a proper jump starter in case of another emergency.
I also asked about keeping the car plugged in even if there is no roof/garage and he said the water insulation around the charging port is good enough to charge even in the rain, so Im just gonna keep it plugged in at all times with the night charging schedule.
Thanks again for everyone's help! Feels good to be able to use the car again :)
 
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Hey guys @ATPMSD and @hiroshiy thanks for the help!
So I tried both of the suggestions (pulling the frunk manually when attaching the power source and using the highest power on my jump starter), but it did not help. Finally, yesterday the road assistance arrived and had it fixed in just a few minutes 😅
Apparently, the power source I was using was way too weak to even open the frunk. My Japanese is not so great, but if I understood correctly, it seems like the 2022 model 3 might be using a slightly different 12V battery (or maybe just some of the cars?) and actually need a better power source to even open the frunk. The guy mentioned he has to go to clients with a similar issue at least once a week, so that makes me feel not so bad about myself anymore :D Gotta go shopping in Amazon to have a proper jump starter in case of another emergency.
I also asked about keeping the car plugged in even if there is no roof/garage and he said the water insulation around the charging port is good enough to charge even in the rain, so Im just gonna keep it plugged in at all times with the night charging schedule.
Thanks again for everyone's help! Feels good to be able to use the car again :)
Please let us know which charger you pick up? Curious about this.
 
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