I've been meaning to share this tip for awhile now... it's a pretty good one.
Now, that I'm back to using keys, I kind of miss the keypad locks back int the Motherland. Back at the officetel, I never had to worry about locking myself... that is, unless, the batteries died!
If you're in your apartment, it's easy to switch out the batteries, but what do you do when you come home, and the keypad doesn't work because the batteries have died? Yikes!
Fortunately, Cyndi's dad figured out the trick: All you need to do is run to the nearest mini-mart and purchase a 9V battery (the boxy one). Place the top of the battery (both circley parts) against the little circular metal "pad." You'll know that everything is working when the keypad lights up and makes some weird noises. You will have to hold the battery for awhile (around 5 minutes?). Caution: The battery will get quite hot (another sign that it's working), so I suggest that you wrap the battery in your T-shirt or scarf.
This is only a temporary fix, though. You'll want to change the AA batteries as soon as you get back into the apartment.
Perhaps this is common knowledge, but we (me, Cyndi, my mom, and sister) were a little astounded. We definitely felt very MacGyver when we charged up the keypad with the little ol' 9V battery. I'm sure there's some simple scientific explanation behind this quick fix, but I lost my ability to comprehend scientific principles after I got into college.