I don't know, if you check any normal electric lock, it has a solenoid that is actually very powerful (much more powerful than what is needed in normal "perfect

I don't know, if you check any normal electric lock, it has a solenoid that is actually very powerful (much more powerful than what is needed in normal "perfect" conditions to open or disengage the lock), I believe this is because the lock builder foresees that over time there will likely be factors (dirt/rust/oxidation/lack of lubrication) that will make the mechanism harder to operate, from what I can get from the article the NFC charges a set of capacitors and that in order to shorten as much as possible this quick charge time they have just barely the power to trigger the latch, while the whole thing seems like nice, it has to be seen how reliable it is over the years in the field. Possibly they could add to the lock/padlock some sort of connector to directly power it in case of need, I remember some "normal" swipe card hotel locks that were powered by AA or AAA batteries that had a (recessed) two pin connector to which you could connect a battery pack in case the batteries were too discharged to trigger the lock open, but for a single lock padlock it wouldn't make much sense (you would be probably locked out of the place where the battery pack is stored).