News
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]
Lifestyle
Tesla makes the cut on California’s newest EV Rebate program
California just signed a $270 million EV rebate into law and it starts this summer.
California Governor Gavin Newsom signed SB 168 into law on Monday, July 13, 2026, creating a $270 million EV rebate program that delivers money directly at the dealership rather than as a tax credit applied months later. The program, called MyFirstEV, is funded equally by California’s state budget and participating automakers, with each contributing $135.5 million to make the math work.
The timing is directly tied to the loss of federal support when the $7,500 federal EV tax credit ended, removing the most significant consumer incentive that had driven EV adoption in the U.S. California, which accounts for roughly one-third of all EVs sold nationally, moved to fill that gap with a state-level replacement.
The rebate structure is straightforward. First-time EV buyers can receive $3,500 off any new battery-electric vehicle with an MSRP up to $50,000. Used EVs priced at $25,000 or below qualify for a $1,750 rebate. The credit is applied at the point of sale, which removes the friction of the old federal system where buyers had to wait for tax season to see the benefit. The program goes live later this summer, with the California Air Resources Board expected to release full participation details next month.
California hits Tesla Cybercab and Robotaxi driverless cars with new law
For Tesla buyers, the implications are mixed. The Tesla Model 3 RWD at $42,490 and the Model 3 Long Range at $47,490 both fall under the $50,000 cap and would qualify for the full $3,500 rebate for first-time buyers. The Model Y, which starts at $44,990 after Tesla’s recent price adjustment, also qualifies. The Model X, Model S, and Cybertruck all exceed the cap and receive no benefit. As Teslarati has reported, the program also includes a carve-out exempting California-based automakers like Rivian and Lucid from the price cap entirely, a provision that puts Tesla at a disadvantage since it relocated its headquarters to Texas in 2021.
Other qualifying vehicles include the Chevrolet Equinox EV, Ford Mustang Mach-E, Hyundai Ioniq 5, Kia EV6, and Volkswagen ID.4.
The Tesla Semi is entering a new Pilot Program with Paper Transport, LLC (PTI), a Wisconsin-based transportation provider. The company will test the Semi’s Long Range configuration through “dedicated operations within the Chicago market.”
Chicago presents an interesting challenge for the Semi, as it will be a colder-weather climate that will test the Semi’s ability to operate in lower temperatures and in potentially large accumulations of snow. This is something Tesla has been testing with the Semi in Alaska and even in Northern California during the colder months, but Chicago will present a truly tough midwestern winter.
Tesla Semi spotted on journey home after winter performance testing
PTI says it is using the Semi to evaluate its strategy of reducing transportation emissions while maintaining performance, reliability, and cost efficiency. These are major arguments for the Semi being introduced into new fleets.
CEO of PTI Tyler Ellison said:
“PTI has been a leader in sustainable transportation solutions for over 15 years. We take a consultative approach to helping customers identify and implement the right transportation solution for their network. Our partnership with Tesla expands our portfolio alongside renewable natural gas and intermodal, giving customers more ways to reduce Scope 3 emissions without compromising service or economics.”
PTI is far from the first company to adopt the Semi within a fleet, as Tesla entered strategic agreements with PepsiCo. and its subsidiary Frito-Lay for a Pilot Program that extended throughout the California region.
Tesla has let companies like those utilize the Semi to determine whether it would be suitable for their operations. Additionally, Tesla gets valuable information regarding the Semi’s performance, knowing what to improve and what is ideal for companies that will utilize the all-electric truck for regional and nationwide logistics.
PTI plans to utilize the Long Range configuration, which is priced at $290,000 and features a range of approximately 500 miles, a three-motor powertrain, up to 800 kW of drive power, and consumption of just 1.7 kWh per mile.
Tesla Semi pricing revealed after company uncovers trim levels
VP of Maintenance at PTI, Bryan Ellen, added:
“We are excited to partner with Tesla, leveraging their ever-evolving technology. We are bullish in our estimation of the parallels available between our dedicated model and the efficiency of their fully electric Class 8 tractor. We anticipate a growing synergy between our businesses as we work to facilitate this sustainable solution for our customers.”
PTI has logged more than 87 million miles using sources like compressed and renewable gas, but now is looking to take it a step further with fully electric operations.
Tesla revealed on Monday that it is building a new autonomous vehicle at Gigafactory Texas, its plant just outside of the City of Austin. This particular vehicle will be geared toward those who are in need of a wheelchair-accessible car that would require no human driver for operation.
According to a new report from Wired, Tesla’s Senior Policy Advisor, India Herdman, told members of the Washington D.C. City Council on Monday:
“We are in development for a purpose-built, wheelchair-accessible autonomous vehicle. We know that paratransit can be very difficult, and people who are confined to wheelchairs permanently should still be able to move around freely, so that is an active product being built by Tesla in Texas.”
This builds upon what CEO Elon Musk said last year on X, which confirmed the company was working on accessible rides within its Robotaxi platform, which currently is confined to the Model Y.
Absolutely
— Elon Musk (@elonmusk) September 19, 2025
Tesla is also developing the Cybercab, which started employee rides last week. However, this vehicle is not necessarily geared toward wheelchair accessibility.
That leaves a major gap in the autonomous ride-sharing program that Tesla is attempting to build; the company has been pretty clear that it does not want to complicate its manufacturing lines by bringing in a wide array of body styles.
However, it seems necessary to have something larger that could help transport people to appointments when they cannot drive. For wheelchair accessibility, the Robovan, which was unveiled at the “We, Robot” event in October 2024, seems to be the most ideal solution:
Herdman did not indicate whether she was referring to the Robovan or if Tesla is building yet another body style that is geared toward full autonomy but also caters to the handicapped.
Tesla might need to develop something specifically for the handicapped in order to align with the Americans with Disabilities Act, which prevents discrimination against people with disabilities in transportation services. Uber was hit with a lawsuit late last year for “refusing to reasonably modify its policies, practices, or procedures where necessary to avoid discriminating against riders with disabilities.”
Tesla would obviously like to avoid this.
It will be interesting to see what Tesla will do with this project, and whether it will introduce something new to the market or just continue with the Robovan.
Tesla makes the cut on California’s newest EV Rebate program
Tesla Semi enters new Pilot Program with interesting challenge
