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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.
Elon Musk
Elon Musk spotlights the Starlink rescue that got through where no cell tower could
Elon Musk spotlighted how Starlink helped rescuers reach five people stranded in Kazakhstan’s snowy mountains.
Elon Musk put a spotlight on a mountain rescue in eastern Kazakhstan on Sunday, writing “Starlink saves lives” in response to a post describing how SpaceX’s satellite internet helped five stranded people reach emergency crews.
The post from DogeDesigner, which had been viewed more than 500,000 times by Sunday afternoon, said the group’s SUV broke down about 15 kilometers from the village of Kystau Kurchum in an area with no usable mobile network. Starlink carried their call for help and kept them in contact with rescuers, who used the connection to locate them.
The rescue itself took place in October. Local outlet YK.kz reported on October 22 that Kazakhstan’s Ministry of Emergency Situations responded to the breakdown in the Kurchum district of East Kazakhstan region and noted that the group stayed in touch through Starlink. Rescuers covered roughly 100 kilometers in a Trekol, a low pressure tire vehicle built for snow and marshland, then escorted the disabled SUV back to Kystau Kurchum. Nobody needed medical attention.
Starlink saves lives
— Elon Musk (@elonmusk) November 8, 2026
Conditions in the region were rough at the time. Kazakh broadcaster Channel 7 identified the five as hunters caught in a snow trap and said satellite communication allowed rescuers to pinpoint where they were. A spokesperson for the East Kazakhstan emergency department said a storm warning was in effect and urged residents not to leave populated areas unless necessary. The same weather stranded seven utility workers repairing power lines in the nearby Kuygan rural district, according to Tengrinews.
Kazakhstan has been one of Starlink’s more notable markets in Central Asia. Teslarati reported in 2024 that Starlink was serving 1,731 of the country’s 1,879 schools, with the country’s Education Minister saying it had set a new standard for internet service in schools.
Rescue stories like this one have followed Starlink for years, usually in places where ground networks fail or never existed in the first place. Then Florida CFO Jimmy Patronis called Starlink a “game changer” for search and rescue crews during Hurricane Milton, and SpaceX and T-Mobile switched on Starlink Direct to Cell in North Carolina to push emergency alerts to phones after Hurricane Helene.
The next target is dead zones for people who do not carry a dish at all. SpaceX is building out Starlink Mobile and earlier this week selected Qualcomm to supply core infrastructure for a planned terrestrial 5G network in the United States, which it intends to pair with its next generation satellite constellation.
Sunday’s post is at least the third time Musk has written “Starlink saves lives” on X this week, following identical posts on November 5 and November 7.
SpaceX plans to attempt what will be a defining moment in rocket reusability on Starship Flight 15.
As Elon Musk announced in a recent X post, SpaceX will attempt to catch both the Super Heavy Booster and the Starship upper stage during the upcoming orbital flight. If successful, it will mark the first time that all parts of an orbital rocket return to Earth intact, a breakthrough Musk has called essential to making life multiplanetary.
SpaceX will attempt to catch both the Super Heavy booster and Starship on the upcoming flight.
If both are successful, it will mark the first time that all parts of an orbital rocket return to Earth intact.
This is the critical breakthrough needed to make life multiplanetary.
— Elon Musk (@elonmusk) November 6, 2026
Previous flights have demonstrated the tower-catch technique with Super Heavy. SpaceX has successfully caught V1 boosters three times (on Flights 5, 7, and 8), with some even reflown. The Ship upper stage has never been caught.
Returning from orbital velocity after deploying payload makes it a significantly harder challenge due to higher energy, heat loads, and the need for precise belly-flop reentry, a flip maneuver, and a final landing burn to settle between the Mechazilla tower’s chopstick arms.
Flight 15, using Booster 22 and Ship 42 (both Block 3 vehicles), is targeted for no earlier than Friday, November 13, 2026, from Orbital Launch Pad 2 at Starbase, Texas. The 75-minute window opens at 4:45 p.m. CT, pending regulatory approval. After hot staging and separation, the booster is planned to return for a catch roughly 6 minutes and 35 seconds after liftoff.
The Ship will insert into a roughly 275 km orbit, deploy 26 advanced Starlink V3 satellites, complete about 14 orbits over more than 22 hours, and—if systems check out—perform a deorbit burn, reentry, flip, and landing burn for a tower catch at approximately T+22 hours 32 minutes.
SpaceX confirms Starship 15 launch window with massive ambitions
A simulation shown during SpaceX’s October earnings call depicted the Ship descending in a belly-flop attitude, flipping upright with a short engine burn, and being captured by the arms:
From simulation to reality
SpaceX is just ONE WEEK away from attempting its most ambitious Starship catch yet https://t.co/nHrxSX6DSz
— X Freeze (@XFreeze) November 6, 2026
Contingency splashdown zones exist in the Gulf of Mexico (booster) and Pacific (Ship) if a catch is not viable. SpaceX has stressed rigorous health checks before committing the Ship to a return-to-launch-site trajectory.
Musk has described the odds of success on this first dual-catch attempt as “more likely than not,” noting a steady stream of additional flights is already scheduled if needed. Full recovery would enable rapid inspection, refurbishment, and reflight—slashing costs and supporting the high launch cadence required for Starlink expansion, lunar missions, and eventual Mars settlement.
As Musk put it, this is “the critical breakthrough needed to make life multiplanetary.”
Tesla Cybercab is going to get some pretty substantial updates, including improvements to efficiency and a new color.
CEO Elon Musk said in a post on X on Saturday that Tesla would be working to refine the Cybercab even more, following the announcement during the week that the company would eliminate the Cybertruck lines within Giga Texas for more Cybercab manufacturing capacity.
“There are efficiency improvements coming that will allow for a 40kWh Cybercab pack,” Musk posted on X. “We will make this in liquid silver, so the colors are not too monotonous.”
There are efficiency improvements coming that will allow for a 40kWh Cybercab pack. We will make this in liquid silver, so the colors are not too monotonous.
The biggest thing most people fail to understand is that there are a very limited number of smart, dedicated people! They can only do so many things.
If we have to maintain a complex production line, supply chain and allocate engineering for Cybertruck, we can’t use those people or factory space and machinery for scaling Cybercab, which is the vehicle that will PROFOUNDLY transform the world of terrestrial transport!
— Elon Musk (@elonmusk) November 7, 2026
A new, more efficient model of the Cybercab will be engineered, which will only help Tesla’s profitability and margins, and it also boosts the argument for why the Cybertruck should be discontinued, at least from a business perspective.
The current Cybercab that operates in the Robotaxi platform in Austin, Texas, has a 48 kWh pack, and it sounds like Musk believes Tesla is on its way to introducing a version that has fewer cells but can manage the same workload thanks to engineering efficiencies.
Credit: Tesla
Musk also doubled down on the decision to prioritize Cybercab production over Cybertruck, which is a decision that has been extremely polarizing within the community, and many fans have made it abundantly clear that they are not particularly pleased with the plans.
“If we have to maintain a complex production line, supply chain, and allocate engineering for Cybertruck, we can’t use those people or factory space and machinery for scaling Cybercab, which is the vehicle that will PROFOUNDLY transform the world of terrestrial transport,” Musk said.
A good look at Tesla’s new Liquid Silver Cybercab, planned with a 40 kWh battery pack following new improvements
😍 https://t.co/IUYsUcCBMs
— TESLARATI (@Teslarati) November 8, 2026
Cybercab is obviously Tesla’s path forward in an automotive sense. It seems that Tesla is less concerned about catering to the passenger vehicle market and is more prone to focus on transforming passenger transportation in a way that prioritizes autonomy. However, this requires some sacrifice on Tesla’s end, and the Cybertruck is unfortunately a victim of this.
Cybercab holds an extremely crucial part of Tesla’s future. With the company already revolutionizing passenger transportation once, this is the next phase, and Cybercab is the path forward.
Elon Musk spotlights the Starlink rescue that got through where no cell tower could
SpaceX will perform Starship double catch attempt with Flight 15
