We wouldnt neither want to have a power adapter, since there is no plug nearby.
I wondering why it’s not possible for @Nuki / @MatthiasK make a new accessory that would allow to charge four AAA battery inside the Nuki Lock without removing them, just by attaching a powerbank every 1-4 months (or everytime you clean the room for your guest to be sure) at the door handle and plug an USB-C into the Nuki-Lock-Battery-Compartment-Version2.
Imagine someone renting out the Nuki locked room for several months: not practicable to change the battery that often. But very easy to change hang a powerbank of night at the door handle, plug it into the battery holder and remove it later. simple. easy. no worries.