Ok, this may be pretty far off but...
Elon Musk tweeted that a solar power tonneau cover option would be available that would provide 15 miles per day. I decided to try using this estimate, given the dimensions of the tonneau cover to figure out what the battery size of the Cybertruck would be...
(Copied from TMC)
There seems to be a lot of guesswork over the design and capabilities of the Cybertruck against what was actually stated, so I’ve created this list from the transcript of the presentation, along with any relevant tweets from Musk. After all, even Neil deGrasse Tyson got it...