The fan community already has that figured out from the standard margin of EVs at "0" miles of range, combined with the percentage state of charge drop from going 500 miles, and the stated efficiency in the presentation (under 2 KWH/mile) and by Elon on twitter (1.7 KWH/mile). This makes it pretty certain that the battery is 1000 KWHr.

Which is double the size of the other trucks to which it was compared to in the article. So either they're making a massive tradeoff or have managed a physics breakthrough (battery weight or density).

That's about 15,000 pounds of battery, correct?

No one knows exactly, but I'd guess closer to about 10000 pounds.

Semi's battery is not going to need as much armor.

Tesla Model Y battery: 81 KWh, 1,700 lbs => 21 lb/KWh. (Lithium-iron phosphate)

Tesla Model 3 battery: 82 KWh, 1,060 lbs => 13 lb/KWh. (Lithium-ion)

1000KWh in lithium-ion: 13,000 lbs.

Teslarati guesses around 15,000 lbs.[1]

A typical semi-truck without trailer weighs 15,000-25,000 pounds. So 15,000 pounds of battery is not hopeless. The Hummer EV weighs 9,000 pounds, after all.

Tesla can, and probably will, sell the "extended range" version for a premium price. There are many semi-trucks that never take long trips. This is mostly a battery cost problem.

[1] https://www.teslarati.com/how-much-tesla-semi-truck-battery-...

Efficiency is key, as with cars

kWh

you can reverse engineer how big the battery is from stated range and efficiency. around 900kwh plus or minus 50