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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.
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“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.
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Tesla has launched a new Vehicle-to-Load (V2L) Outlet Adapter for Premium Model Y vehicles in the United States, meaning you can now power devices like laptops or light strings with your vehicle’s battery.
It appears the capability will be available for any Model Y Premium trim, including those that were purchased prior to the Adapter being launched. It will also only impact Juniper Model Y vehicles, so the first-gen owners will unfortunately not have access to this capability.
If your Model Y was purchased before Tesla renamed the trim levels to “Premium” and “Standard,” it does not seem to be compatible. My Model Y is technically a Premium build, as it is the Long Range All-Wheel-Drive. However, Tesla says it is not compatible with my vehicle.
🚨 Tesla has launched the Outlet Adapter for Model Y Premium in the U.S., enabling V2L capability for all Premium trims (that’s what it appears to be as it is available for purchase with all Premium trims)
It’s available for $80. 2.4kW max power and rated for 120v, 20A pic.twitter.com/lDxlVIk5s8
— TESLARATI (@Teslarati) August 14, 2026
For $80, you can now utilize your car as a portable charger for small appliances or devices. This is perfect for things like tailgates, concerts, or camping, as you can now plug in devices that you might use. Those string lights for camping? That laptop for the other games that are on at the tailgate?
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They’ll both utilize energy from your Tesla’s battery to be powered. This is the first time Tesla has expanded the capability to vehicles outside of the Model Y Performance and Cybertruck. However, this feature has been highly requested by owners for an extended period of time.
Tesla launched the Outlet Adapter in China last year:
Tesla China rolls out Model Y L V2L adapter, and it’s free for early owners
You will need the Mobile Connector to operate the Outlet Adapter: the Outlet Adapter will plug into the main housing of the Mobile Connector, where the appropriate adapter to charge your vehicle will plug in.
It is rated for 120 volts and 20 amps, and has a max power rating of 2.4kW.
You can buy it here from Tesla for $80.
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Tesla is nearing its long-awaited unveiling of the all-electric Tesla Roadster, a new report from The Information claims, as the company has said several times this year that the event would take place “soon.”
Now, it appears there is movement on Tesla’s end regarding when it will happen.
The report says that Tesla will unveil the Roadster as soon as this month with a SpaceX version that will utilize cold-gas thrusters to help the vehicle float for a short period of time. This is something CEO Elon Musk has talked about with the Roadster for years.
🚨 The Information is reporting this morning that Tesla is ready to unveil the “flying” Roadster as soon as this month
It’s almost here, folks. pic.twitter.com/IdL4atsucQ
— TESLARATI (@Teslarati) August 14, 2026
Additionally, due to the delays, Tesla explored “a variety of designs” for the Roadster, potentially planning to abandon the design it showed off for the first time in 2017 and adopting an entirely new aesthetic.
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According to The Information, Tesla considered utilizing a repurposed Model S Plaid and even wanted to upgrade the look to something like a Lamborghini Countach.
We’ve heard all of these things before, including teases about the date and how “soon” the Roadster will finally be ready to be shown off to the world (for the second time). Musk said that the event would occur in April, then May, then Chief Designer Franz von Holzhausen continued to say it would be coming “soon.”
We do expect to see the Roadster by the end of the year, and now with this new report swirling, it appears it could be sooner rather than later.
The wait has been incredibly long, but there is likely a good reason for it. Tesla’s desire to make the Roadster the craziest vehicle on the road was non-negotiable, and it likely took a lot of time and resources to develop and perfect into something that was safe and suitable for a vehicle like this.
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Tesla finally got its Nevada Robotaxi Permit but with a few catches hard to miss
Nevada granted Tesla’s robotaxi permit, but capped the fleet at just ten vehicles for now.
Tesla has received its robotaxi permit in Nevada, more than two months after regulators closed the public comment period on the company’s application. News of the approval surfaced Wednesday night when Tesla investor and longtime company watcher Sawyer Merritt posted a copy of the interim order, and the Nevada Transportation Authority’s own carrier registry now lists the permit, AVNC Permit 002 under Docket 26-05015, as active for Tesla Robotaxi, LLC.
Tesla asked Nevada in June for authority to run up to 5,000 vehicles in Clark County within a year, however the permit the NTA issued is initially capping Tesla at ten fully autonomous vehicles and confines them to a defined geofence along the Las Vegas Strip corridor. Any expansion of that operating area, or any increase to the fleet size, requires the NTA’s approval first.
Tesla has received its Autonomous Vehicle Network Company permit in Nevada.
The Nevada Transportation Authority says that operations are limited to a maximum fleet of 10 fully autonomous vehicles and shall be conducted only within the Authority-approved Operational Design… https://t.co/Cxfd6GIfDk pic.twitter.com/iOO6wSZkHF
— Sawyer Merritt (@SawyerMerritt) August 13, 2026
The order also sets rules that look more restrictive than what Tesla runs in Austin. Rides are barred on roads with posted speed limits above 45 miles per hour, pickups are off limits within a quarter mile of Harry Reid International Airport without separate authorization, and every vehicle has to carry visible “Robotaxi” markings while notifying riders before each trip that no one is driving. The order also requires “appropriate human supervision”, language that suggests Nevada isn’t ready to let Tesla offer the rides without a safety monitor that it has run in parts of Austin since January. As with standard protocol with robotaxi services, Tesla must report any accident, system failure, or vehicle that becomes stranded on a Nevada road within five business days.
Tesla is entering a market Nevada already knows well. Zoox, the Amazon owned robotaxi company, has run its own autonomous vehicle permit in the state since last year, building up to roughly 100 vehicles and 350,000 rides along the Strip. That history likely explains why the NTA started Tesla at ten cars rather than the fleet size the company asked for. The agency has a template for scaling a permit up once a company proves out its safety record.
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Tesla’s Nevada application first surfaced in June, when the company filed for the permit alongside plans for a maintenance hub in southwest Las Vegas. The company has said it won’t meaningfully scale its robotaxi fleet anywhere until FSD v15 ships, expected in late 2026 or early 2027, which makes the ten vehicle cap less of a constraint today than it might look on paper. For now, Tesla has the legal right to start Nevada rides. Whether it starts before FSD v15 arrives is a separate question the permit doesn’t answer.
Tesla launches V2L Outlet Adapter for Premium Model Y in the U.S.
Tesla Roadster unveiling nears, and it will fly: The Information
