If you watch the whole video he does it more “for real” later on, plugging the casing into a power source to simulate a battery discharging… Plus I’ve had some of these PowerCheck batteries, and they were not old, it was like… 2017? So maybe they rebooted it for a short time at some point?? Anywho, if you pressed really hard it did work I think, but also I think I was doing it wrong for a long time as well lol
Well as they say, you can put lipstick on a pig…