www.BoundAnna.com

I just found this apparently new electric-timer-lock (see attachment) for sale.

https://www.aliexpress.com/store/produc ... 99770.html

Does anyone have experience with this? Failures? Does it unlock upon battery
drained -- how long does that take? Suggested safety measures -- daisy chain
two or three together in case of a "type-oh" (20 hours instead of 20 minutes)?

There is a thread about them here: http://forum.boundanna.net/board/viewto ... =7&t=11252
(Warning, contains shots of the innards and instructions on how to take them apart. So if you dont wantto knowthat, don't visit the 3rd page)
They're not bad, but I wouldn't trust them with my life.