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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’s AI lead Ashok Elluswamy doubled down on the company’s strategy regarding Full Self-Driving’s speed settings, and owners are definitely confused.
Earlier versions of Full Self-Driving allowed owners to set a max speed that the vehicle could travel while operating under the semi-autonomous driver assistance platform. This allowed more customization for the driver, giving them the ability to experience FSD’s robust performance with their own personal preferences.
Speed is massively important for obvious reasons — it’s not only a question of keeping the vehicle occupants comfortable by traveling at a safe speed, but it’s also something that could contribute to a ticket or infraction from law enforcement.
With the release of FSD v14 last year, Tesla removed the ability to set a max speed and instead opted for five Speed Profiles, ranging from “Sloth,” the most conservative, to “Mad Max,” the most aggressive and spirited. These profiles not only control speed, but also how frequently the vehicle will execute passes, perform lane changes, and other contributing factors.
The removal of the Max Speed setting was a major complaint amongst the Tesla community because it left owners scrambling for a way to experience suitable behaviors while traveling at an appropriate speed. Most felt the driving profiles would be a good indicator of the behaviors, while speed would still be left up to the discretion of the driver.
Instead, Tesla’s Speed Profiles determine both, and the constant tinkering of how they behave has been a major bottleneck and point of confusion for both owners and the company. From update to update, the Speed Profiles will change, sometimes more drastically than others. Some owners have complained that the “Standard” profile is too fast, while others have experienced “Mad Max” traveling below the speed limit:
What has happened to Mad Max?
At one point it was going 32 in a 35. Traffic ahead had pulled away considerably https://t.co/bjKvaMVTNX pic.twitter.com/aaZSWmLu5v
-— TESLARATI (@Teslarati) January 24, 2026
These things change with each update, but the big complaint is that owners are on the hook for any tickets that come from FSD’s infractions; that’s the caveat of the suite being named FSD (Supervised). It ultimately means the driver is responsible, and the automaker has no liability when it comes to speeding tickets or general traffic infractions.
It is the driver’s responsibility to take over or adjust based on this.
Elluswamy essentially confirmed that there are no plans to bring back Max Speed control, because it is what he referred to as “an anti pattern.” He then echoed something that CEO Elon Musk has started to really push with FSD, and that’s the idea that Tesla is really honing in on the preferences of the driver.
Max speed control is an anti pattern.
We are working on better learning of user’s implied preferences.
— Ashok Elluswamy (@aelluswamy) August 3, 2026
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Owners were confused by Tesla’s decision, stating that there must be a better way, especially considering disengagements for incorrect speeds are common:
This…. is not the way
— Kyle Conner (@itskyleconner) August 4, 2026
😭 I appreciate this mentality ! But currently the no.1 reason I disengage in Australia is incorrect speed zones.
— Ryan’s Model Y (@ryanjaycowan) August 3, 2026
This is fine but you need to start accepting liability for speeding tickets then. https://t.co/lyCgdA83gQ
— Jeremy Judkins (@jeremyjudkins_) August 4, 2026
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Okay https://t.co/nOvoXQkNg1 pic.twitter.com/jGRtF2xtox
— Chad Moran (@ChadMoran) August 3, 2026
From personal experience and using FSD for over 72 percent of my driving miles since v14 was released late last year, I make Speed Profile adjustments constantly. If FSD is traveling a tad too quickly, I will scale it back, and if it’s too conservative, I’ll make it more aggressive.
I don’t complain about making the Speed Profile changes too frequently, but it would certainly be nice to have it happen less frequently. There are far too many times I am concerned about getting a ticket, even in Standard mode.
The biggest issue for me, personally, which seems to be echoed throughout the community, is the fact that Tesla’s goal is to minimize disengagements. Many drivers are stating that speed is a major reason for disengagements.
However, Tesla is not willing to bring back this one level of input because it would technically be a regression.
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Whether it’s right or wrong in your opinion, it is what Tesla is going with, and it seems like it has pivoted quite a bit from its other strategies for minimizing interventions by pushing its AI to behave in a way that would fit the occupant’s personal preferences.
Tesla is one of several automakers whose vehicles qualify for an awesome new first-time EV buyer incentive program in California.
The Golden State launched the MyFirstEV incentive program, which helps those buying an electric vehicle for the first time with a $3,500 incentive on new-inventory purchases of a Model 3 or Model Y.
First-time electric vehicle buyers in California can now get $3,500 off eligible Model 3 and Model Y new inventory vehicle purchases.
To be eligible, you must place your order on or after August 3, 2026 and take delivery while funds are still available. The incentive applies to… pic.twitter.com/yuXF00XA50
— Sawyer Merritt (@SawyerMerritt) August 4, 2026
The incentive requires an order on or after August 3, and delivery must be taken while the program is still being funded. California has set aside $135.5 million to help strengthen its SEV market and support automotive innovation.
Incentives are offered at the point of sale, and used EVs are also available for a partial incentive of $1,750. Half of the $3,500 and $1,750 incentive amounts are covered by California, with the other half being covered by participating OEMs.
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Additionally, rules apply for MSRP and how the vehicle will qualify for the incentive. Any vehicle from a non-California headquartered OEM must have an MSRP of $50,000 or less. Used vehicles must be priced at $25,000 or less and must be at least two model years older than the year of purchase.
The cars must also be purchased from manufacturers as certified pre-owned vehicles. Private dealerships are not eligible.
In total, California expects to incentivize over 73,000 ZEVs.
Participating Manufacturers
Fourteen total automakers are participating in California’s MyFirstEV program:
- Chevrolet – Launching August 2026
- Ford – Launching August 2026
- Honda – Launching September 2026
- Hyundai – Launching August 2026
- Kia – Launching August 2026
- Lexus – Launching September 2026
- Lucid – Launching August 2026
- Mitsubishi – Launching November 2026
- Nissan – Coming Soon
- Rivian – Coming Soon
- Subaru – Launching September 2026
- Tesla – Launching August 2026
- Toyota – Launching September 2026
- Volvo – Coming Soon
Elon Musk’s space exploration company, SpaceX (NASDAQ: SPCX), is set to report its earnings for the second quarter today in what will be its first-ever earnings call since going public in July.
SpaceX is trading down roughly 25 percent from its IPO. These early stock signals are usually a bit tumultuous, and considering this is the first company actively launching rockets that is available on the stock exchange, investors might have a tendency to be a bit skittish.
However, there are going to be some details that investors will hear for the first time today on the earnings call. Here’s what to look for:
Wall Street Expectations
Revenue is expected to fall somewhere around $6.8 billion, and will be heavily driven by Starlink, which is SpaceX’s widely popular satellite internet platform that has been adopted by numerous airlines, cruise ships, and other maritime operations. It is also available for consumers at home or in their cars.
Earnings Per Share (EPS) expectations fall at a net loss of $0.23 per share. Wall Street sees this as a total net loss of roughly $1.9 billion.
EBITDA is expected to come in between $2 billion and $2.1 billion.
What Investors Want to Know
Tesla uses the Say platform to help work with both retail and institutional investors to answer relevant and quality questions that address concerns or questions that they might have.
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However, SpaceX is doing things differently, as the company launched its own Investor Relations website where these questions are being fielded. Just like the Tesla questions, they seem to be less focused on the operational tasks and overall progress of the company, and more novelty.
Here are the top five:
- Has the team thought about what possibilities there are with your mascot Asteroid? Whether it’s starting additional foundations for kids in its name, helping kids learn about space, etc. Kids are our future, and Asteroid would be a fun and easy way to help.
- Baby Asteroid is already making a difference through charity around the world. Could SpaceX take it even further with programs that inspire kids to explore space?
- SpaceX has some legendary vehicle names. Would you ever allow the public to name a Starship, even knowing there is a 99% chance it becomes Shipy McShipface?
- When can we expect to see more footage of the Human Landing System?
- Will Asteroid (your mascot) go to Mars?
SpaceX will report its earnings today, August 4, at 4:30 P.M. EDT.
Tesla’s AI lead doubles down on FSD’s speed strategy, and owners are confused
Tesla qualifies for awesome new first-time EV buyer incentive in California
