One of the Tesla Model 3’s biggest mysteries may have been revealed: how the $35,000 car will achieve a high distance per charge on a smaller battery pack. In a recent livestream, one Tesla insider explained the company is planning to use a “4416” cell to power the car, which would pack more energy storage into the same space.

“Somebody reached out to me very recently and they gave me some info about the Tesla Model 3,” Ben Sullins from Teslanomics said to viewers on Monday. “My hunch I had earlier, turns out to be pretty accurate. The Tesla Model 3 will have new, larger battery cells than the previous models.”

The “4416” name refers to the size of the cell, which would measure 44mm by 160mm. Following its previous pattern, Tesla would usually name the cell “44160,” leading to speculation that this will be the final name. These cells are placed into modules, which are in turn are placed in packs. These packs are placed inside the car to make it drive.

On the Model S and Model X, Tesla uses an “18650” cell, which measures 18mm by 650mm. These are packed into 16 modules and placed inside the car. A “44160” cell, on the other hand, would require just four modules.

“That would mean the cell is bigger and more energy dense, which means you can have less of them to achieve the same energy output,” Sullins said.

Tesla has taken extra effort to reduce the size of battery required to achieve an acceptable range in the Model 3. The new car, set to launch later this month, is by far the cheapest the company’s ever produced. That’s no small feat: Tesla claimed in April 2016 that its batteries cost $190 per kilowatt-hour (kWh), making them an expensive component on even an entry-level 75kWh Model S. For the Model 3, the lightweight frame has been designed to reduce aerodynamic drag, meaning Tesla can save money and use a battery capable of storing less energy to achieve a range of over 200 miles per charge.

The Model 3 central console.
The Model 3 central console.

A recent photo of the Model 3’s interior showed the company had achieved impressive boosts in efficiency. The console pictured shows a Model 3 with a range of over 300 miles. Sources have previously told Teslarati that the car will come in both 60kWh and 75kWh configurations, meaning it’s likely this car has the larger battery. The Model S with 75kWh pack, though, only offers a range of around 250 miles. If Tesla is using a denser “44160” cell, it would explain how the company has managed to achieve a respectable range on a budget.

It was previously suggested that Tesla would use the “2170” cell in the Model 3, an advanced battery produced at the company’s Gigafactory. These are used for the Powerpack and Powerwall products, which store renewable energy for use during downtime to avoid blackouts. Using the same battery for its cars could theoretically simplify production. However, last month Musk claimed the Model S and X would not change battery form factor, meaning the “2170” would not appear on the company’s premium-range vehicles.