A denser battery pack adds 69 miles without adding weight or trunk space

The same car, two different packs

The current Tesla Model 3 comes in 2 trims, Rear Wheel Drive and Long Range All Wheel Drive, both filed with the United States Environmental Protection Agency for model year 2024. Both trims share the identical body, the same 4,000 pound EPA test weight class and the same 15.0 cubic foot trunk, called luggage volume in the filing the agency keeps. What differs is what sits inside the battery pack, the part of the car that stores the energy the motor draws on.

What specific energy means

The measure that explains the difference is specific energy, how much energy a pack packs into every kilogram it weighs, in watt hours per kilogram. The Rear Wheel Drive pack holds 126 watt hours per kilogram, the agency filing states, and the Long Range All Wheel Drive pack holds 174, in the identical car. Across the wider model year 2024 market, real packs from 5 named cars range from 126 up to 188 watt hours per kilogram, the agency filing shows.

An independent battery engineering reference site tracks the industry mean pack specific energy climbing from about 146 watt hours per kilogram in 2019 to about 175 by 2026, roughly 3.4 watt hours per kilogram a year, close to where the Model 3 Long Range pack already sits.

The weight a denser pack does not add

From the amp hour capacity and voltage the agency also files for each pack, the Rear Wheel Drive pack works out to about 60 kilowatt hours, a unit for larger amounts of energy, and the Long Range pack to about 81 kilowatt hours, 35% more total energy in the same body. Dividing each figure by its own specific energy gives a rough pack weight, and the 2 come out close, the denser pack if anything slightly lighter. The government states vehicle weight only in 500 pound bands above 3,000 pounds, so this cannot be stated more precisely than that. A pack that packs more energy into the same kilograms does not have to add weight to add range.

What that buys a driver is 341 miles instead of 272, 69 miles further, in the identical trunk and the identical weight class, the agency filing states for both trims.

The space a pack also takes up

The same idea has a second dimension, volumetric energy density, how much energy a pack packs into every litre of space it takes up, in watt hours per litre. That number matters for cabin and trunk space rather than for weight. An independent battery engineering reference site lists a 2010 Nissan Leaf at 49 watt hours per litre and a Zeekr 001, with its 140 kilowatt hour pack, at 350.

The average new battery electric car sold in the United States in model year 2024 already reached 292 miles of range, the agency trends report states, almost 4 times the 2011 average. The United States Department of Energy sets a 2030 target of 300 miles minimum range while cutting pack cost below 75 dollars per kilowatt hour and charge time below 15 minutes, aiming to keep the range Model 3 owners already have while making the pack that delivers it cheaper and faster to fill.