For people eyeing a T480s, make sure both batteries inside don't have too much degradation. At some point, the switch from one battery to the other doesn't work properly and the laptop will most times suddenly switch off when battery #1 reaches 0%, even if the 2nd one is at 100%, no matter how many recalibrations you do.
Maybe it will work. But mine has more than 50% degradation on both, and I run Nixos from RAM and don't do serious work on it, so I don't care about the shutdowns.
