Eneloops would only last about 3 weeks. And disposable last 2 months. This door is used a lot and since it has Zwave and a door open sensor it sends info on every open.
Bonus, since it can handle the lipo AA batteries that put out 1.8v and it gives the motor more oomph I made the battery pack give 7.2v and it never sticks anymore.
This is a garage-door so its not critical access but is used a lot.
If the house was on fire I would just step out through a window frame after smashing the window with the nearest solid object I can find.
But I use regular keys and my front door can be locked/unlocked without a key from the inside.