After the trailer weight, capacity is generally 48,000 lbs, or roughly 21800 kg. At 167 Wh/g, they could fit about 3,640 kWh on the trailer. Enough to fully charge around 364 P100Ds.
The cost would be a mere $364,000 at $100/kWh.
There was a post a while back, either here or on Reddit, that...