Specifications for Voltage of Smart Lock 3.0

Nuki Smart Lock 3.0 uses 4 rechargeable batteries AA 1,2V.

To avoid continuous replacement of batteries, we replaced them with a stabilized supply power 6V 24W.

The sound of the driver seems not regularly flowing when (un)latching door. Therefore, I’m wondering which is the maximum voltage specification for the SL3.0 to improve the driver.

The stabilized supply power can be set 6 or 7,5V. I would expect a better performance with 7,5V (if that is feasible for the electronics).


A forum search might help. It’s not about voltage, but how much power the supply can provide (especially during short peaks). A permanently powered Nuki PowerPack is the best solution.


Hi Jurgen,

today I tested three voltage settings: 5V, 6V and 7.5V (using the stabilized power supply 24W).

Definitely, with 5V, the Nuki is with low power.
With 6V, as it worked for more than 1 month, the driver is working but it is stressed when unlocking the door. It was not able to open the door in such cases.
7.5V definitely works properly. The driver is more fluid and it is always able to open the door.

I believe that electronics is preserved by a diode/voltage stabilizer, while the full power supply is directly connected to the driver. In this case, everything should work without impacts.