I'd call Tesla. Some vehicles do fine with agm batteries others seem to know or need "programming " to accommodate them.
Model 3 low voltage battery warning
- Thread starter JeffKeryk
- Start date
I'd call Tesla. Some vehicles do fine with agm batteries others seem to know or need "programming " to accommodate them.
I think there are AGM, LiFePo4 and Lithium Ion batteries. The first two are re-placements for each other. The third is a whole different animal. I think.
Exactly it. Definitely dependent on delivery voltage and some can even have the battery capacity set for battery management. I'm sure it's possible to set both on a Tesla.
Here's the mobile service process:
Texted me at 7:45 AM and got here about 10 minutes later. Pulled up in a black Model S with "Tesla Service" paint.
I had the windows down, doors open and frunk open. Nice young man; offered him a coffee.
He told me what he was gonna do: replace battery, check trunk harness (operates trunk button, camera, etc) and quick overall checkup.
The battery swap was simple - remove cowl and battery cover, remove 1 lead, lift pass side rear seat cushion and disconnect main battery plug, swap battery and put stuff back. You can also use tablet to "shut down" car, but that is to reset the persistent warning message. He did not and it was not necessary. I could do this in 10 minutes or less, given I had the new battery.
Then he checked harness and told me what to watch for. Backup camera delay and delay opening trunk. He mentioned our car was very fast to respond. Checked tires (these cars are heavy!) and a few other things. He did say our car was one of the best early cars he has seen. Even filled windshield warsher fluid.
Nice young man; polite, offered to answer any questions and gave me a little advice. He started on the mfg line in Fremont and now was a mobile tech. Single father with a young daughter. Impressive, hard working and a pleasure to meet. Of course I tipped him a $20 for his lunch. He earned it. The bill was $123 because the battery was over 4 years old. You pay with the CC you have on line for Supercharging.
I am glad our Model 3 is back in the pink. I got so sick of gas stations, $5+ gas, all those stupid buttons, dials and crap on the Lexus dashes. You need a PhD to operate old skool cars. Dangerous if ya ask me. On the freeway, you step on the gas and wait (like forever) for the car to slowly accelerate. Back and forth on the gas and brake pedals. Sheesh.
Texted me at 7:45 AM and got here about 10 minutes later. Pulled up in a black Model S with "Tesla Service" paint.
I had the windows down, doors open and frunk open. Nice young man; offered him a coffee.
He told me what he was gonna do: replace battery, check trunk harness (operates trunk button, camera, etc) and quick overall checkup.
The battery swap was simple - remove cowl and battery cover, remove 1 lead, lift pass side rear seat cushion and disconnect main battery plug, swap battery and put stuff back. You can also use tablet to "shut down" car, but that is to reset the persistent warning message. He did not and it was not necessary. I could do this in 10 minutes or less, given I had the new battery.
Then he checked harness and told me what to watch for. Backup camera delay and delay opening trunk. He mentioned our car was very fast to respond. Checked tires (these cars are heavy!) and a few other things. He did say our car was one of the best early cars he has seen. Even filled windshield warsher fluid.
Nice young man; polite, offered to answer any questions and gave me a little advice. He started on the mfg line in Fremont and now was a mobile tech. Single father with a young daughter. Impressive, hard working and a pleasure to meet. Of course I tipped him a $20 for his lunch. He earned it. The bill was $123 because the battery was over 4 years old. You pay with the CC you have on line for Supercharging.
I am glad our Model 3 is back in the pink. I got so sick of gas stations, $5+ gas, all those stupid buttons, dials and crap on the Lexus dashes. You need a PhD to operate old skool cars. Dangerous if ya ask me. On the freeway, you step on the gas and wait (like forever) for the car to slowly accelerate. Back and forth on the gas and brake pedals. Sheesh.
JHZR2
Staff member
If the Tesla is set up like my accord hybrid, the 12v battery is perpetually undercharged and continuously damaged.
It’s not uncommon for me to find my 51R on my accord at 12.0v or less after sitting a while.
I have a voltmeter in mine. In routine use the 12v bus is only around 12.5V unless the HVAC or headlights are on. That’s undercharged.
In past cars that were older euro designs with lower voltage regulator settings I’d run AGM sometimes because the battery was in the trunk and I had hoped for greater reliability. Those AGM were indeed always up to the task.
That said, if these cars are going to severely undercharge batteries, and probably only really need them for clocks and power door unlock, I’d stick with flooded as cheap as possible. And replace it more often…
FYI I replaced the tiny 51R in our 06 TSX with the Accord V6 size 35 (I forget). All I did was bend the tang on the top bracket. Of course the plastic tray could not be used... It is a tight fit.
On the 4 banger Accords, of course the V6 battery fits fine.
There really isn't much of a point if it is not used to crank the engine. EV and hybrids use DC->DC converter to convert high voltage to the 12V charging one. It is used for electronics only and not for starting any motor. They probably still last the same either size.Can you upgrade the tiny 51R to a 35 or 24F?
A 2018 EV should have a main battery that last 15 years minimum, unless it is Nissan Leaf or any other air cooled garbage. Unlike NiMh battery, the Li Ion battery in EV should just have reduced range instead of failure.
It really "depends". I like buttons and dials as you don't need to move your eyes away from the road, just remember with muscle memories where the buttons are and what they do.
Probably just me, I hate one pedal driving. Keeping your feet at the same position for a long time really is tiring.
On a "simple" car there aren't that many dials and buttons. Late model Lexi, and other cars, have a plethora of manual controls. This can be confusing.
The Tesla uses a tablet with the main controls in plain sight. The sub menus can be confusing.
Having said that, voice controls beat the snot outta either one.
Mine was replaced on April 29, 2024 and I got the warning today. The car has been on the charger for last 4 weeks and was not driven until today. I don't drive that car too often but the OEM battery lasted almost 6 years before giving warning. Did I get a bad battery?
Not sure… Tesla gave me a 5 year warranty. Lemme know what you find out…
my plug in voltmeter is in the other car; once I have that I will see if I can read the resting battery voltage to see if it is indeed weak. Even if the car was not driven for 4 weeks, there should not be any appreciable drain. Especially if the car was on the wall power all the time. From reading over the internet, it looks like the reset procedure is the same as replacement procedure. I don't know if I am in the mood to get my hands dirty.
If the cigarette lighter is switched how would you know it is not charging? Seems once ignition is on the 12v battery is being charged.
not sure how to test that. I put the cigarette lighter voltmeter and the voltage showed 14.8
I disconnected the wall power, still showed14.8
I went into the menu and powered off, still showed 14.8 Although I do not know what that "power off" state is. Is it turn off the screen? It immediately, comes back as soon as I put the foot on the brake pedal. It did not even go through any reset sequence like it does with 3 finger salute. But there is a special menu button for turning off the display for cleaning purpose, so I would think power off must be something more.
Is there "eqvt" of ACC mode where I can get the battery voltage showing up on the plug? May be not because may be computer gives power to the lighter only if the low voltage battery is being charged.
Theoritically, it might not even be possible to measure resting battery voltage. 14.8V is charging voltage.
At least the battery is charging i.e. my "alternator" is still working.
I disconnected the wall power, still showed14.8
I went into the menu and powered off, still showed 14.8 Although I do not know what that "power off" state is. Is it turn off the screen? It immediately, comes back as soon as I put the foot on the brake pedal. It did not even go through any reset sequence like it does with 3 finger salute. But there is a special menu button for turning off the display for cleaning purpose, so I would think power off must be something more.
Is there "eqvt" of ACC mode where I can get the battery voltage showing up on the plug? May be not because may be computer gives power to the lighter only if the low voltage battery is being charged.
Theoritically, it might not even be possible to measure resting battery voltage. 14.8V is charging voltage.
At least the battery is charging i.e. my "alternator" is still working.
Same deal with a gen 2 Prius - a weak 12V will cause the car to act weird. Thankfully, there’s more than one place to get a JIS S46B24R AGM now.
When I went to my appointment, they told me it will take 3 hours! I said I will wait and set up the laptop for work. About 15 minutes later, he tells me "You are all set; that was a bad battery; we replaced it"
After driving half way to home, I asked via app that there was no charge and of course it was all covered.
Tesla tech came to our house and installed the tiny 51R (4 banger Honda size) battery. Was about $120? He also checked the car over for common issues. He declared our 2018 a really good one for fit and finish.
