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An inside look at Tesla’s P100D battery pack: more cells, 102 kWh capacity, backwards compatibility in mind
New details of Tesla’s mysterious P100D battery pack, which Tesla CTO JB Straubel once described as having notable changes in battery module and pack technology, and a “complete redo on the cooling architecture”, have emerged thanks to Jason Hughes’s latest project.
Hughes posted photos of a dismantled 100 kWh battery pack, which he obtained through the purchase of a salvaged Tesla P100D, that reveal an increase in the number of 18650 lithium-ion cells being packed within each battery module. Hughes also discovered a surprising increase in battery capacity beyond 100 kWh, and what appears to be a replaceable connector that allows Tesla to retrofit older vehicles with the newer battery pack.
More 18650 Battery Cells
As outlined in Hughes’s blog post, Tesla was able to fit more of its cylindrical 18650 lithium-ion battery cells into each of the 16 modules making up the P100D battery pack. It’s worth noting that Tesla has maintained a relatively similar form factor on battery packs produced for Model S and Model X vehicles since their introduction. Regardless of the vehicle’s model version – be it a P85, a 60, 75D, or 90D – the uniform skateboard design of the battery pack allows for ease of production, as Tesla can manufacture a single-style pack that can be installed across its fleet of vehicles. Under that same notion, Tesla has also been able to create ‘unlockable features’ by software limiting vehicle range depending on the option purchased by the customer. In other words, Tesla installs the same battery pack into like-kind vehicles (e.g. Model S 60 uses the same pack as Model S 75).
Tesla P85 battery pack module vs. P100D module [Credit: Jason Hughes via @wk057]
Hughes’s dissection of the P100D battery shows that Tesla leveraged the same design concept by distributing a total of 8,256 battery cells across the 16 modules making up the battery pack, bringing total capacity up to the advertised 100 kWh number. However, and much to Hughes’s surprise – he had previously criticized Tesla for providing less battery capacity than what’s perceived by way of the vehicle’s nameplate – Tesla actually provided 102.4 kWh of capacity on the P100D pack, representing a 2.4% increase over what’s marketed.
Backwards Compatible Design
Tesla has also, seemingly, taken into account the ability to retrofit new battery packs onto older vehicles by using the same high and low-voltage connectors across packs. According to Hughes, “the pack itself has the same high-voltage connection, the same low voltages connectors, and the same cooling connector.” However, Hughes notes that there’s subtle changes on the P100D pack that would require a new part in order for it to be retrofittable onto non-P100D vehicles.
“The [P100D] pack has the newer ring around the high-voltage connector. So, it’s plug-and-play (for the most part, firmware and config changes needed) on the Model X and refreshed Model S, however it would require a different spacer ring on the high voltage connector. Tesla even has a part number for it, so it should be pretty simple to put into any Model S/X.” says Hughes.
What about that new P100D battery cooling architecture?
Well. It’s not magic. Tesla did improve battery cooling in the new P100D 100 kWh battery pack. And Tesla did provide a redone architecture, but it isn’t one of mythical proportions.
Hughes reveals Tesla’s approach to improve battery pack cooling was to use shorter and thinner cooling loops per battery module, thereby improving the rate of heat dissipation. Unlike most other electric car makers who do not “prime” their vehicle’s batteries through the use of a thermal management system, Tesla pumps fluid through the battery module to regulate the temperature of its battery pack in order to bring them to optimal operating temperatures. By ensuring the lithium-ion cells operate within ideal temperatures, Tesla is able to provide the best performance possible, while ensuring cell longevity.
Tesla P100D battery module cooling loops [Credit: Jason Hughes]
Tesla has adjusted the functionality of a crucial climate feature as Winter weather has started to arrive throughout some parts of the United States. The new feature was highly requested by owners.
Tesla has a Cabin Overheat Protection feature that helps keep the temperature regulated if it reaches a certain threshold. Inversely, it can be used in cold weather as well, which will automatically warm the cabin if it sinks to a temperature that is too low for the owner’s comfort.
This is a great way to keep the cabin either warmed up just enough or cooled down just enough so that it never gets too hot or too cold. Extreme temperatures could damage certain parts of the vehicle or damage personal belongings that are kept inside the car.
Overheat protection is a great thing to have in hot climates like Arizona or Texas, especially with the Premium trims of the Model 3 and Model Y, which feature a glass roof.
Many owners appreciate the feature, but they argue that using it at home will utilize too much energy, especially during extreme temperatures. For a while, many Tesla fans have requested an option to disable this feature when the car is parked at home, which the company recently added, according to Not a Tesla App.
The feature is part of Software Version 2025.44.3, and the release notes state:
“You can now choose Exclude Home when Cabin Overheat Protection or No A/C is enabled.”
Tesla has been great at listening to what owners want with new features, and this is one that will reserve some charge and prevent unnecessary utilization of available power, especially as the car is parked at home. If owners want to condition the cabin or get the car ready for operation with a comfortable interior, they can utilize the Tesla app to adjust the climate.
Tesla CEO Elon Musk revealed today on the social media platform X that legacy automakers, such as Ford, General Motors, and Stellantis, do not want to license the company’s Full Self-Driving suite, at least not without a long list of their own terms.
“I’ve tried to warn them and even offered to license Tesla FSD, but they don’t want it! Crazy,” Musk said on X. “When legacy auto does occasionally reach out, they tepidly discuss implementing FSD for a tiny program in 5 years with unworkable requirements for Tesla, so pointless.”
I’ve tried to warn them and even offered to license Tesla FSD, but they don’t want it! Crazy …
When legacy auto does occasionally reach out, they tepidly discuss implementing FSD for a tiny program in 5 years with unworkable requirements for Tesla, so pointless. 🤷♂️
🦕 🦕
— Elon Musk (@elonmusk) November 24, 2025
Musk made the remark in response to a note we wrote about earlier today from Melius Research, in which analyst Rob Wertheimer said, “Our point is not that Tesla is at risk, it’s that everybody else is,” in terms of autonomy and self-driving development.
Wertheimer believes there are hundreds of billions of dollars in value headed toward Tesla’s way because of its prowess with FSD.
A few years ago, Musk first remarked that Tesla was in early talks with one legacy automaker regarding licensing Full Self-Driving for its vehicles. Tesla never confirmed which company it was, but given Musk’s ongoing talks with Ford CEO Jim Farley at the time, it seemed the Detroit-based automaker was the likely suspect.
Tesla’s Elon Musk reiterates FSD licensing offer for other automakers
Ford has been perhaps the most aggressive legacy automaker in terms of its EV efforts, but it recently scaled back its electric offensive due to profitability issues and weak demand. It simply was not making enough vehicles, nor selling the volume needed to turn a profit.
Musk truly believes that many of the companies that turn their backs on FSD now will suffer in the future, especially considering the increased chance it could be a parallel to what has happened with EV efforts for many of these companies.
Unfortunately, they got started too late and are now playing catch-up with Tesla, XPeng, BYD, and the other dominating forces in EVs across the globe.
Tesla is backtracking on a strange adjustment it made to its in-car Navigation feature after numerous complaints from owners convinced the company to make a change.
Tesla’s in-car Navigation is catered to its vehicles, as it routes Supercharging stops and preps your vehicle for charging with preconditioning. It is also very intuitive, and features other things like weather radar and a detailed map outlining points of interest.
However, a recent change to the Navigation by Tesla did not go unnoticed, and owners were really upset about it.
For trips that required multiple Supercharger stops, Tesla decided to implement a naming change, which did not show the city or state of each charging stop. Instead, it just showed the business where the Supercharger was located, giving many owners an unwelcome surprise.
However, Tesla’s Director of Supercharging, Max de Zegher, admitted the update was a “big mistake on our end,” and made a change that rolled out within 24 hours:
The naming change should have happened at once, instead of in 2 sequential steps. That was a big miss on our end. We do listen to the community and we do course-correct fast. The accelerated fix rolled out last night. The Tesla App is updated and most in-car touchscreens should…
— Max (@MdeZegher) November 20, 2025
The lack of a name for the city where a Supercharging stop would be made caused some confusion for owners in the short term. Some drivers argued that it was more difficult to make stops at some familiar locations that were special to them. Others were not too keen on not knowing where they were going to be along their trip.
Tesla was quick to scramble to resolve this issue, and it did a great job of rolling it out in an expedited manner, as de Zegher said that most in-car touch screens would notice the fix within one day of the change being rolled out.
Additionally, there will be even more improvements in December, as Tesla plans to show the common name/amenity below the site name as well, which will give people a better idea of what to expect when they arrive at a Supercharger.
Tesla adjusts crucial feature as winter weather arrives
Tesla CEO Elon Musk sends rivals dire warning about Full Self-Driving
