A Deep Dive into Battery Tech: LFP, NMC and New Solid-State Batteries and Their Advantages

By Karan Singh
Not a Tesla App

Samsung SDI, who already produces some of Tesla’s 4680 battery cells, has recently begun testing new solid-state batteries.

Solid-state batteries are expected to be smaller, lighter, cooler, and safer than current cell formats that are used in electric vehicles. There’s a lot of potential and possibilities in solid-state batteries.

Let’s dig into exactly what these new batteries are, and why everyone seems to fuss all over them on the big news channels every time a company makes an announcement.

Regular Batteries

The biggest thing to understand about solid state battery is how they’re different from regular batteries is terms of materials and design. We’ll dig into regular batteries first, and then get to solid state batteries.

Today, Tesla’s EVs – and EVs in general, use one of two types of batteries – LFP or NMC. LFP batteries are composed of Lithium Iron Phosphate (LiFP on the periodic table), while NMC is composed of Nickle Manganese Cobalt (NiMnCo). Tesla uses LFP batteries in its standard range vehicles, while their longer-range or performance siblings use NMC battery composition.

The biggest difference here is price and performance – LFP has a more stable chemistry and less degradation but also has a lower energy density. Meanwhile NMC performs better, outputs more energy, has a higher energy density, but isn’t as chemically stable and will degrade faster.

These chemical differences also aid with temperatures – NMC batteries perform better in more extreme weather conditions such as extreme cold or extreme heat – much better than their LFP siblings.

Both of these types of batteries also contain a liquid electrolyte – a wet medium that is electrically conductive and enables the movement of the ions in the battery pack, but won’t conduct electricity. So, with all that aside, let’s take a look at what solid state batteries bring to the table.

Solid State Batteries

Solid State Batteries don’t contain that liquid electrolyte. That’s already a huge change – because a large portion of the weight and density increases in regular battery packs actually originate from that heavy liquid. The replacement of that liquid is a stable, solid electrolyte, generally in the form of glass or ceramics.

Essentially, that frees up space and makes it easier to cool the batteries – so much so that solid state batteries today are used in smartwatches and other wearable devices – even pacemakers. In fact, that space saving is so large, that a solid-state equivalent of an LFP or NMC battery would use up 1/10th of the space, with a similar reduction in weight.

Additionally, solid state batteries don’t need all the additional equipment for monitoring, controlling, and cooling the liquid electrolyte – the pack is a solid block that can be cooled similar to a PC part – like a CPU.

The removal of the liquid electrolyte can also improve vehicle safety. We’re sure you’ve been told never to puncture a battery pack – that’s because when the electrolyte is removed, LFP and NMC batteries can experience thermal runaway – they have no way to cool themselves, and this heat reaction spreads throughout the battery, leading to a fire. In addition, the electrolyte tends to be flammable and toxic – making battery fires a truly dangerous, but still rare, phenomenon.

The electrolyte liquid – even though it does the important job of moving the ions around – actually can and will do permanent damage to the components of the battery, causing corrosion or build up over exceptionally long times. That’s exactly how you get battery degradation!

A solid electrolyte solves all these problems. Mostly. Even the solid electrolyte can degrade over time but will last an exceptionally long time. That’s why many companies advertise 20-year lifespans, and with considerable energy density.

Samsung’s recent solid-state breakthrough has them mentioning a 20-year lifespan with 500Wh/kg. Tesla’s newest 4680 cell is 244 to 296Wh/kg right now. Samsung has also mentioned a massive charging speed improvement – 9 minutes. That’s probably a 20% to 80% number, rather than a 0% to 100% number – as charge speeds at the far end of the curve tend to slow down considerably to protect the battery, while exceptionally low states of charge are uncommon.

Where is the Solid State?

We did say we already use solid state batteries elsewhere, like in wearable devices. But why not cars? They’re expensive. In fact, very, very expensive to manufacture at the size and scale needed to power EVs. Tesla and its battery suppliers, including Samsung, CATL, and LG, have been prototyping and working on their own solid state battery projects over the years.

Once they figure out how to scale these up, we could see drastic improvements in vehicle range and longevity, alongside improved charging times. But I wouldn’t expect them to show up right around the corner – it may take several years for engineers and scientists to work everything out, and another few to figure out to mass produce it.

NHTSA Probes Tesla’s Robotaxi Plans; Seeks Answers on FSD in Poor Weather

By Karan Singh
Not a Tesla App

As anticipation builds for Tesla’s Robotaxi network debut in Austin, potentially just a few short weeks away, the National Highway Traffic Safety Administration (NHTSA) is turning its official eye onto Tesla. The ask? How will Tesla’s FSD handle the unpredictable realities of challenging weather?

The NHTSA Request

The NHTSA has sent a formal letter to Tesla, which was made public on May 12th, requesting detailed information about Tesla’s Robotaxi service. The NHTSA inquiry centers specifically on the safety and performance of FSD when faced with reduced visibility conditions like rain, fog, and sun glare. The request is tied to an ongoing NHTSA investigation, which was initiated in October 2023, examining Tesla’s FSD and Autopilot suite following incidents in poor visibility.

Tesla’s executives, including Elon Musk, have previously stated that the company is full steam ahead to launch Robotaxi in Austin this June. However, NHTSA’s pointed questions come even as Tesla has recently discussed its plans to work on region-specific and weather-specific FSD training.

Tesla’s executive leadership acknowledged the need to adapt the system to diverse environmental and weather conditions. Now, regulators want specifics on how Tesla intends to address environmental conditions and how that translates to operational safety for the fleet.

Request Breakdown

NHTSA’s letter outlines a need for detailed information from Tesla before the service launches and covers several key areas. We’ve broken this down into various sections below:

Deployment Scale

NHTSA is looking for the exact number of vehicles and models that will be part of the initial Austin fleet, and what the projected service availability times would be for said fleet. Tesla has previously said it’d launch with 10-20 Model Ys, but looks like NHTSA is looking for additional details.

Oversight

In terms of oversight, NHTSA is looking to confirm whether the Robotaxis will operate under real-time supervision of Tesla’s employees, either remotely or in-vehicle.

This is a question on our minds as well. A recent app update suggested that Tesla could have a driver in the vehicle, but it wasn’t clear whether this was referring to Tesla’s own fleet or customer-owned vehicles. The only thing we have heard officially from Tesla is that Tesla “may” use remote support, but that they were still looking into it.

Adverse Weather Capabilities

This is the meat and potatoes of the request - how will Tesla ensure safety during sun glare, fog, heavy rain, snow, or dust? What specific protocols are triggered if poor visibility is encountered mid-trip? Will the vehicle pull over or call home and cancel rides?

Sensor Technology

Surprisingly, NHTSA is looking for details regarding the vehicle the Robotaxi sensor suites and how Tesla intends to use those sensors to ensure safe operation under varied conditions. NHTSA has had previous submissions from Tesla in regard to its sensor suite and how it uses the technology, so it feels odd that they are requesting another batch - but this could be related to the use of the next generation of FSD (Unsupervised).

Compliance

Does Tesla’s FSD system adhere, either fully or partially, to established industry standards for autonomous driving? This likely refers to the NHTSA Automated Vehicles for Safety guidebook, which lays out the “L0 to L5” driver assistance vs automation system.

Future Expansion

Finally, NHTSA is looking for the timeline for enabling Robotaxi functionality on vehicles not directly owned or controlled by Tesla. Tesla has already come out and said that customer-owned vehicles wouldn’t be allowed on the robotaxi network until 2026, but obviously, NHTSA wants to hear directly from Tesla and likely has more specific questions covering a wide variety of potential issues.

These questions will likely have to be answered with considerable amounts of data and justification for the NHTSA. Once all that is done, Tesla will be in a better position to receive regulatory approval at a larger scale than just within the city of Austin or the state of Texa with the NHTSA’s backing.

Successfully addressing this letter will be the key for Unsupervised FSD moving forward, but Tesla hasn’t issued a public response to the agency’s letter, and likely won’t in a public manner. So we’ll have to wait and see how the launch of the Robotaxi network pans out next month.

FSD V13.2.9 Rolls Out for HW4 as Part of Tesla’s 2025.14.6 Update

By Karan Singh
Not a Tesla App

After an 84-day wait since the last FSD update, Tesla has finally begun rolling out a new version of FSD V13 to its AI4-equipped vehicles. This new release, V13.2.9, is rolling out to all vehicles, including the Cybertruck.

Unfortunately, since it’s a minor point release (from V13.2.8), the release notes are the same, and Tesla hasn’t included a change log or changed what’s coming in the future.

Software Update 2025.14.6

The FSD update is rolling out with Tesla software update 2025.14.6. Interestingly, update 2025.14.6 is seeing a wider distribution and is also being made available to vehicles without FSD and outside North America. For those vehicles, this update just includes bug fixes.

TCU Fix

There’s one fix in particular that’s expected to be included in this update, according to a message from Tesla Service. In earlier 2025.14 updates, there was a bug in some vehicles that prevented some vehicles from falling asleep properly due to a Telematics Control Unit (TCU) issue. This bug caused additional battery drain since some of the vehicle’s systems remained on.

Tesla Service said they planned to include a bug fix in update 2025.14.6, but it hasn’t been confirmed whether the fix actually made it out in this release.

Early Access Users and More

FSD v13.2.9 was first rolled out to Tesla’s standard Early Access group, including well-known community members and content creators. It has also reached participants in the newer, Texas-based Early Access Program, suggesting that the update is relatively stable and may serve as a foundation for upcoming FSD releases.

Tesla could be intending to use the Texas Early Access Program to test various features, perhaps related to the upcoming Robotaxi network launch in Austin. While this is plausible, it is merely speculation, and we’ll be keeping a close eye on that group to see what exactly Tesla does.

HW3 Users

While Tesla has recently been including FSD updates for HW3 and HW4 in the same release, this update does not include any changes for HW3 users. HW3 vehicles that are receiving this update are staying on FSD V12.6.4, which means that whichever fixes this update includes they’re specific to FSD V13 or HW4.

Point Release - Not Much New

Being a point release, V13.2.9 isn’t expected to introduce any major new capabilities. Tesla hasn’t provided specific release notes detailing changes from V13.2.8.

Hopefully, Tesla has taken into account recent user feedback on V13.2.8 about lane centering and lane selection, and this update addresses some of those issues. However, early feedback is that those issues are still present.

There is always potential for a more substantial update in the near future, so keep your fingers crossed, but after such a long wait, we expected more to be included. It seems like Tesla may have felt the need to address a bug in this release instead of waiting for the next major release, which is expected to either be FSD V13.3 or FSD V14.

Update 2025.14.6

FSD Supervised 13.2.9
Installed on 6.1% of fleet
398 Installs today
Last updated: May 14, 10:30 am UTC

Roll Out

The fact that Software Update 2025.14.6 is going out wider than the Early Access audience suggests that Tesla is confident in this release and that it likely only includes very minor changes. We expect this update to continue going out over the coming days.

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