Advertisement



Tesla’s 12V batteries set to receive major improvements through software update

MEDICALJMP

Well-known member
First Name
Jeff
Joined
Apr 28, 2020
Messages
276
Reaction score
406
Location
Omaha, NE
Vehicles
Toyota Avalon, Rav4, Tri-motor Cybertruck
Occupation
Nurse
Country flag
Tesla’s 12V batteries set to receive major improvements through software update
By Simon Alvarez




https://www.teslarati.com/tesla-12v-battery-improvements-ota-update-elon-musk/

The Tesla ownership experience is intended to be as convenient as possible, with the vehicles themselves needing very little maintenance and practices like charging being effortless with the Supercharger Network’s plug-and-play nature. Yet even amidst all these conveniences, Tesla owners have cited a notable pain point in their ownership experience: their cars’ 12V battery.

Similar to traditional vehicles, Teslas utilize a conventional 12V battery to power components like emergency blinkers, airbags, seatbelt pre-tensioners, and the infotainment system. Typical 12V batteries last about 3-4 years under normal use in a fossil fuel-powered vehicle, but among Tesla owners, especially those who drive frequently, the lifespan of 12V batteries have been reported to go down to as short as 1-2 years.

Adding to the inconvenience is the fact that Teslas currently do not have a feature that notifies owners about the health of their cars’ 12V batteries. Tesla owners have responded to this by requesting for an update that would allow them to view the current state of their vehicles’ 12V batteries. One such request was posted on Twitter recently, with Tesla enthusiast @TeslaVibes stating that such a feature needs to be implemented in a future update.

Interestingly enough, Elon Musk completely agreed with the Tesla enthusiast’s request. The Tesla CEO added that major software improvements are set to be released for vehicles’ 12V batteries, which should allow them to last longer. “Couldn’t agree more — major software improvements are already in place to extend its life & more coming,” Musk wrote.


Considering Musk’s post, it seems that an update that would include 12V battery health warnings is all but confirmed. Such a feature will likely be universally appreciated by Tesla owners, as it could address a particularly infuriating part of the electric car ownership experience. Such a feature, if any, would definitely reduce the instances of owners running into major inconveniences when their vehicles’ 12V battery dies.

Elon Musk’s Twitter post suggests that Tesla is well aware of the limitations that 12V batteries still bring to the EV ownership experience. With this in mind, it would not be surprising if the company comes up with a superior alternative for 12V batteries in the coming years. Tesla, after all, is known for its quick pace of innovation, and the 12V battery is certainly an area that is in great need of some innovation.

It should be noted that the earliest versions of the original Tesla Roadster did not use a traditional 12V battery. Instead, Tesla opted to utilize a portion of the vehicle’s main lithium-ion battery pack to supply 12V for the all-electric sports car’s accessories and lights. The system was quite novel, but the idea was later dropped in favor of a more traditional 12V battery. Conventional 12V batteries were initially used for the original Roadster 2.0, and in every vehicle that Tesla has released since.
 

TI4Dan

Active member
First Name
Dan
Joined
Feb 23, 2020
Messages
27
Reaction score
33
Location
MT. USA
Vehicles
Ram 2500.GMC 1500, LandRover Diso 1, GT750, Electra Glide Ultra Classic
Occupation
Retired, added 5 days to my weekend
Country flag
The 12V battery seems to be in my experience has been built in such a way that life is shorter, but this may not be the case all the time. I worked for a Transportation Agency for 26 years that had a fleet of almost was at 500 buses. Typical a group 31 battery was used which most heavy duty trucks also use. All of our buses use four each batteries to give power to interior lighting which is heavy load, fair box, surveillance cameras
and many other computer driven loads that never turn off.
This is what we call a parasitic load and the current draw was
so high if the vehicle was not used with in 5 days it may not have enough energy to start the engine. As a Class one tech I advisied
them of the problem, it took over a decade to change to a higher quality battery which helped but loads still went up with newer buses.
My personal truck was just a GM 1980's 3/4 type, which I used on occasions, with family a two door truck just did not fit our need.
So it was parked the majority of the time the battery that was in was used when I bought the truck over three years earlier. The truck would sit up to months and it would start right up I never thought much about it. The battery was dated and it lasted 7 years in my use from being my only vehicle to needing to haul
home improvements stuff. I purchase a high end battery has a replacement. I would like to mention something here, I am well versed in battery technology, anything new in batteries I need to know. Before I install a battery I always charge a new battery even when the parts store says they are ready for use..well how long was it sitting on the shelf? Flood batteries will lose some of it's charge just sitting on the shelf. Batteries that come with out acid and must be added,( most of you will not see this) the battery must be charged for at least 24 hours for use. So back to my old truck with a $175 dollar battery newly installed. My truck would not start after sitting for just 2 weeks, what happened?
I kept pulling out the battery and charging it up load testing to make sure it had the capacity to start my V8 engine. This went on for months, this included me looking for a parasitic load which it does not have since it's old school tech of 1980's.
I finally decide to put in the battery we use in our buses, I bought the lowest quality I could find, The new battery could sit for months and start my truck with ease.
My current truck a 4 door diesel which uses two batteries cost me around $400 bucks to replace when due, so it's a big deal to me about build design and quality.
Batteries degrade over time no matter the compositions but I believe the batteries of today are more compact and lead acid batteries sulfate which falls to the bottom of the cell and after time it will short out the cell. In the USA there are all two or three battery manufactures have not looked it up in a while but Johnson Controls build the majority of the mass marketed car batteries. If they build a great battery profits will drop, You don't remember the old batteries they used to make and hey you got 3-4 years on your car battery it was time. I say it's a big lie to keep selling a batteries that could be built to a higher standard.
The tech is there but sincerity is not. I hope Elon changes the battery in some way to improve the reliability. If you made it this far thanks for hanging in, this is one area i am unhappy about we should be well past this issues.
 

ajdelange

Well-known member
First Name
A. J.
Joined
Dec 8, 2019
Messages
1,540
Reaction score
1,405
Location
Virginia/Quebec
Vehicles
Tesla X LR+, Lexus SUV, Toyota SR5, Toyota Landcruiser
Occupation
EE (Retired)
Country flag
You get 4 - 5 (sometimes more and sometimes less) tears out of the battery in you ICE vehicle if you put in a 5 year battery but if you put in a 1 year battery from Crappy Tire you get much less. The same is doubtless true of the 12 V battery in your Tesla. If they put in a better battery, which, naturally, costs more, they'd last longer. Remember that they never get assaulted with the cranking load as an ICE battery does. It would also doubtless help if the battery were a bit larger than the puny 30 Ah ones they are installing now.

One of the problems with modern batteries, even the long life ones, is that when they fail it is sudden. Car cranks like a trooper on a cold winter morning but when you come out of work, even though it is much warmer it is dead, dead, dead.

All this aside people carry on as if having the 12 V battery replaced is major surgery. It isn't. WIth a 10 mm socket on an electric drill and a 10 mm spanner you should be able to replace it in about half an hour.


It get's discharged according to how you use 12V loads so there isn't much you can do about that. But it gets charged by a sophisticated DC/DC converter over which the vehicle has great control. If improvements in the software that controls that converter can be made then it might be possible to improve the life cycle through gentler charging.

Finally, many owners choose to swap out the lead acid and replace it with a Li ion equivalent (Ohmu). Rather dear, though.
 
Last edited:

Crissa

Well-known member
First Name
Crissa
Joined
Jul 8, 2020
Messages
771
Reaction score
694
Location
Santa Cruz
Vehicles
2014 Zero S, 2013 Mazda 3
Country flag
The 12v battery supplies the communications system with power, as well as the brakes and hazard lights.

The new Zeros follow Tesla and Nissan in that configuration. It's just a small battery.

But since it's being used for communications, it often gets drained more quickly than intended - and its these cycles of discharge and recharge (or overcharge) which is the problem.

My Zero uses the main DC-DC board to power everything. But that puts stress on the DC-DC board and means that you're losing battery power all the time (I lose over a percent a day). But it also means that in an accident, the emergency lights do not function, and regulations now require that ABS and the hazard lights function independently of the vehicle's main power system.

For Zeros, there's been some which are parked in just such a situation that the communications never turn off and they drain out the battery. That may be similar to the Tesla issue.

The other one is that charging a battery to full all the time isn't good for it. So if you're driving alot, you're taxing the communications system (which talks every time you start the car) and you're charging the battery.

So they need to come up with a better cycle of test/charge/quiet so the battery is there when you need it.

-Crissa
 

TI4Dan

Active member
First Name
Dan
Joined
Feb 23, 2020
Messages
27
Reaction score
33
Location
MT. USA
Vehicles
Ram 2500.GMC 1500, LandRover Diso 1, GT750, Electra Glide Ultra Classic
Occupation
Retired, added 5 days to my weekend
Country flag
You get 4 - 5 (sometimes more and sometimes less) tears out of the battery in you ICE vehicle if you put in a 5 year battery but if you put in a 1 year battery from Crappy Tire you get much less. The same is doubtless true of the 12 V battery in your Tesla. If they put in a better battery, which, naturally, costs more, they'd last longer. Remember that they never get assaulted with the cranking load as an ICE battery does. It would also doubtless help if the battery were a bit larger than the puny 30 Ah ones they are installing now.

One of the problems with modern batteries, even the long life ones, is that when they fail it is sudden. Car cranks like a trooper on a cold winter morning but when you come out of work, even though it is much warmer it is dead, dead, dead.

All this aside people carry on as if having the 12 V battery replaced is major surgery. It isn't. WIth a 10 mm socket on an electric drill and a 10 mm spanner you should be able to replace it in about half an hour.


It get's discharged according to how you use 12V loads so there isn't much you can do about that. But it gets charged by a sophisticated DC/DC converter over which the vehicle has great control. If improvements in the software that controls that converter can be made then it might be possible to improve the life cycle through gentler charging.

Finally, many owners choose to swap out the lead acid and replace it with a Li ion equivalent (Ohmu). Rather dear, though.
I think you are right about the charging program when the inverter tops of the 12v battery or is it load based. Tesla vehicles
I imagine have more of a parasitic load then a Ice vehicle.
I went to a friends home to help him with his wife's car when parked over the weekend it would not start on monday morning.
I discovered the problem it was excessive parasitic load from a digital clock, I disconnected and it no longer happened.
I assume the load is much greater on a Tesla vehicle with all
of it's tech (cameras and computers) that can't be turned off.
A higher capacity battery would increase the life with maybe
modified charging profile.
 

ajdelange

Well-known member
First Name
A. J.
Joined
Dec 8, 2019
Messages
1,540
Reaction score
1,405
Location
Virginia/Quebec
Vehicles
Tesla X LR+, Lexus SUV, Toyota SR5, Toyota Landcruiser
Occupation
EE (Retired)
Country flag
One aspect of it with the Teslas is that the WiFi (or, if WiFi is not available, cell)modems are on all the time so that the car can check in with Mother Ship which is does from time to time. Drivers often use programs like TeslaFi or Stats to accumulate data from their cars. These poll the car more frequently and result in more phantom drain. And the biggie - Sentry mode in which the cameras are active. There is conceptually no reason that ICE cars with an equivalent level of bells and whistles would not be as susceptible to such drain but I don't think even the fancy ICE cars have all this neat stuff.

But this thread isn't about phantom drain. It is about 12V battery longevity. As long as the main battery is at SoC above 20% it will keep charging the 12V battery as needed.
 

Advertisement




Advertisement







 
Top