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Why Tesla’s lead acid 12V battery needs to be lithium-ion based
It’s a prominent issue surrounding the electric vehicle market that the old-school lead acid battery just isn’t appropriate for new technology vehicles. Many users of electric vehicles, especially Tesla owners, have cited concerns with the poor performance of their 12V or low-voltage battery, oftentimes requiring annual replacement.
In contrast, a lead acid battery in a traditional internal combustion engine (ICE) vehicle generally has a 4 year life-cycle, but why?
RELATED: Tesla Model S 12V Lithium-Ion battery replacement (up to 70% lighter, 4x life)
First off, some of the most important factors to consider in longevity of a battery are “cycle-life”, environmental conditions, discharge/charge rates and calendar-life; cycle-life is how many times the battery can be drained and recharged in its life. Environmental conditions include temperature and humidity. Discharge/charge rates are the amperages going out of and into the battery respectively.
There are two major differences between the way an ICE vehicle uses its 12V battery and the way an EV uses its 12V battery:
“OFF” state discharge and cycling frequency
ICE Vehicle: generally has a very low 12V load while the vehicle is in the “off” state, often this load doesn’t exceed a few watts and doesn’t present a major challenge for the 12V battery to maintain.
Electric Vehicle: The 12V load while in the off-state is often much higher due to advanced computer systems that are running to maintain the high-voltage battery, keep vehicle “connected” (all EV have some remote access features), maintain charging and BMS (Battery Management System) communications, etc. In fact a Tesla Model S/X puts about 50 Watts of load on the 12V system when the vehicle is in the “off” state. 50 Watts equals about 4.5 Amps of discharge on the 12V battery, this drains the battery down relatively rapidly and requires the 12V battery be “recharged” by the high-voltage battery regularly, this usage pattern results in many cycles being placed on the battery.
“ON” state utilization and purpose
ICE Vehicle: The 12V battery is used to initiate the ICE (start the car) and is designed for putting out large amounts of current to accommodate this process. Once an ICE vehicle is in the “on” state, it relies on an alternator to power all of the 12V sub-systems and also maintain the voltage of the 12V battery.
Electric Vehicle: The 12V is subjected to (practically) no additional load while the vehicle is being turned “on”, and although most vehicles are designed with DC/DC converters (which act as alternators) it is often an engineering design choice to reduce load on the DC/DC converter by minimizing the frequency with which it is utilized. This also extends the driving range of the vehicle because none of the precious high-voltage battery capacity is being shunted to non-driving tasks. Due to this usage profile the 12V battery is subjected to relatively low discharge and recharge currents.
When you combine the high number of cycles and the low current requirements of the electric vehicle 12V battery system you arrive at a completely different battery need than that of an ICE vehicle. Lead Acid batteries are very good at high discharge and low cycle count life-styles, this is their bread and butter and this is where they last a long time and provide the most bang for the buck (cheap cost and decent product life-cycle), but they aren’t lasting in electric vehicles.
The electric vehicle 12V battery system is one that is best suited by a battery capable of tremendous cycle-life as the main design goal. The battery chemistry that suits this usage scenario best? Lithium! Lithium battery technology is specifically very good at being cycled many times and continuing to provide minimal capacity loss and degradation. This, along with reduced weight, is why these batteries are used for the high-voltage battery packs, cell-phones, laptops, medical equipment and cars where batteries are being cycled frequently and longevity is important.
Editor’s note: This post was submitted into our network by Tesla Model S owner Sean Scherer. Having suffered an unfortunate incident in his Model S that left him stranded because of a faulty 12V battery, Sherer began on a mission to create a lithium-ion based 12V battery solution that was not only more reliable than the traditional lead acid battery, but better suited for the demands of a Tesla Model S, Model X, and electric vehicles in general. He began BattMobile Batteries, who have made it their mission to improve adoption of electric vehicles by solving some of the small details that has been missed by EV manufacturers.
We’ve also included a video tutorial on how to replace the Model S 12V battery.
Tesla has officially launched the Model Y L in the United States and Puerto Rico for $61,990. It is the longer-wheelbase version of the Model Y, and has been available in China since last year.
Tesla brings the Model Y L to the U.S. just months after it phased out the only pure SUV in its lineup, the Model X. It is slightly longer than the Model Y configurations that are already available in the U.S., and features a three-row, six-seat setup with Captain’s Chairs being among the many features that make this a truly fantastic offering.
The Model Y L is priced competitively at $61,990, and features 325 miles of range and a 0-60 MPH in just 4.4 seconds.
Tesla also added a handful of new features that are not available in even the Premium Model Y. Here’s a full list of its features:
- Heated/Ventilated Front Seats with Powered Thigh Cushion
- Heated/Ventilated Captain’s Seats in Second Row with Powered Armrests & One-Touch Fold
- Heated Third-Row Seats with Power Recline, One-Touch Fold & Child Seat Anchors
- Improved Airflow, Increased Efficiency, More Range
- 89 cubic feet of trunk space
- Upgraded Acoustic Glass and Suspension to Minimize Road Noise
- Adaptive Damping for a Smooth, Stable Ride
- Staggered Tires for Enhanced Grip
- Larger Tailgate for Better Rear Visibility and Bigger Windows Overall
- 16″ First Row and 8″ Second Row Touchscreens
- 19-Speaker Immersive Tesla Audio
- 50W Wireless Charging Pads with Active Cooling and Charging Ports for All Other Seats
- FSD Supervised and Integrated Grok AI
Tesla is also delivering these first units as a “Launch Series,” which comes with additional features, such as:
- Door Trim Puddle Lights
- Suede Dashboard Wing
- Exterior and Interior Badging
- Floor Mats
- Sill Plates
The launch of the Model Y L in the U.S. marks a huge offering from Tesla to U.S. consumers. People have been calling for Tesla to bring a larger car to the U.S., and it needed it more than ever now that the Model X is gone.
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- Credit: Tesla
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- Credit: Tesla
It is a huge accomplishment for Tesla to get the Model Y L to the U.S., and after reporting strong deliveries today, it will be interesting to see how this car impacts future quarterly delivery reports.
Deliveries for the Model Y L “Launch Series” are slated for September or October of this year.
Tesla just told us twice that the Model Y L is coming to the U.S., and two social media posts definitely just tipped the company’s hand, as if they wanted it to be any other way.
The two social media posts basically confirm that the slightly longer version of the Model Y will be heading to the United States soon, and many have speculated that the company could launch the vehicle as soon as this weekend.
The first post was directly from Tesla, and it showed an incredibly long Dachshund, with words above that said, “Looking forward to the long weekend.”
Looking forward to the long weekend pic.twitter.com/URzH6zOUdn
— Tesla (@Tesla) July 1, 2026
Anyone who knows Tesla knows the company loves to troll its fans and have fun, and this is a perfect example of that. While not a direct acknowledgement, Tesla is very involved on social media, especially CEO Elon Musk’s platform X, and the company is well aware of what is being discussed within the community.
With recent sightings of Model Y L test mules in California, peeks of the vehicle at Giga Texas, and a large call for the car to come to the U.S., Tesla is simply stoking conversation with this.
However, the company also made another move that was recognized on social media. Tesla has a large gallery that includes photos of its products so media and others can use them. This gallery applies to the U.S. market specifically, unless otherwise specified.
Tesla uploaded a Model Y L to the Gallery last night:
This looks like a Model Y L https://t.co/TpnBwrLmH9
— TESLARATI (@Teslarati) July 2, 2026
This seems to be another indication that the Model Y L is coming to the United States.
Musk said last year that the Model Y L could make its way to the United States late this year, but it was not something that was set in stone by Tesla. The company definitely needs to establish something in the SUV market that is larger than the Model Y, and the Model Y L might be the answer.
Even still, there are consumers out there who would love Tesla to develop something even larger, like a competitor to the Tahoe or Expedition. Tesla has not really given much of an indication that it will go in that direction.
Tesla is using the vehicles’ internal microphones to improve build quality, Vice President of Engineering Lars Moravy revealed recently.
It’s no secret that Tesla is always finding ways to make its manufacturing operations more efficient, accurate, and valuable. Constantly trying to make its cars better, the company has never placed any restrictions on what it will do to improve everything from panel gaps to paint.
As Teslas have been driving autonomously on the property of the Gigafactory Texas plant for a while now, Moravy revealed to Herbert Ong in a new interview that cars rolling off production lines now autonomously navigate themselves through a bumps, squeaks, and rattles (BSR) portion of the line. This helps to identify any loose or improperly installed internal parts.
The cabin’s microphones, which are used for a variety of things in ownership, simultaneously monitor any noises inside the vehicle while it rolls through the BSR portion of the production line. Moravy actually revealed that Tesla is trying to build “Full Self-Hearing,” an AI system that will detect minor imperfections so they can be corrected before delivery.
It’s no secret that build quality is something that Tesla struggled with as it scaled to a fully massive production operation that manufactures over 1.6 million vehicles per year. However, in recent years, especially, there have not been as many complaints. Tesla has truly improved upon its build quality and paint quality over the past several years, especially in the U.S.
Tesla’s ‘megacasts’ are key to massive build quality improvements
While those improvements have been evident, there are still some complaints; no automaker is perfect with this. But this step will now ensure that every single car that rolls off the production lines at Gigafactory Texas will be void of any creaks, squeaks, or squeals when it leaves the factory.
This measure is one of the most unique we’ve seen in terms of a strategy to avoid build quality issues, but it is not exclusive to Tesla.
Ford uses acoustic analysis AI to find abnormalities in seat motors, climate control units, and other components. Suppliers and OEMs will also use microphone arrays or particle velocity sensors in end-of-line stations.
The full interview with Lars Moravy is available below:
🚨 If you’re a Tesla investor, this is one interview you don’t want to skip. The full video posted below.
Jeff Lutz @thejefflutz and I sat down with Tesla VP of Engineering Lars Moravy, and it was packed with insights!
A few of the biggest takeaways:
• Cybercab is expected to… pic.twitter.com/fhYSr2dCqP
— Herbert Ong (@herbertong) July 1, 2026
Tesla brings Model Y L ‘Launch Series’ to the U.S. at $61,990
Tesla just told us twice that Model Y L is coming to the U.S.
