Saw this one today, customer bought a house and wanted me to rekey all of their locks, was wondering why the electronic lock didn’t work. I have never seen this in my life. You pulled AA batteries out of it, why would you put noticeably smaller batteries in it? AA and AAA alkaline batteries do actually put out the same amount of voltage at 1.5V but AAA will only last half as long and being shorter might mean that the lock only works intermittently. Those springs are designed to push up against a longer battery. Most locks use AA or 9V batteries. If in doubt it probably says in the battery compartment what kind of battery you are supposed to use!
While on the subject of batteries and locks I should also throw this out there: not all batteries of the same form factor put out the same voltage. A AA battery might put out 1.2 to 1.6V. If the lock requires 4 batteries and is expecting 1.5 volts from all of the batteries but only getting 1.2 it is a voltage drop of over 1V, and it might not be enough for the lock’s motor to turn. Rechargeable batteries don’t usually put out 1.5V, they put out 1.2V, and the lock will not work reliably. Failed electronic locks are one of the top reasons I get called for lockouts. Most devices are still designed for alkaline batteries. Lithium batteries are of different chemistry but put out 1.5V too. Alkaline batteries maintain the correct voltage for longer too, rechargeable batteries will quickly lose voltage. That is fine for a flashlight, it only gets dimmer. For things with integrated circuits and stuff that needs a more regulated voltage it will more likely stop working altogether.
When you change the lock’s batteries keep your eye out for corrosion of the terminals. Rust is obviously bad. If you see a white powder that is probably leaked battery acids which solidify into metal salts. Careful cleaning that stuff, if you scrape it off the spring terminal it could fly in your eye. Vinegar will dissolve it and then you can wipe it up. Don’t go being an idiot and pour vinegar into the battery compartment, apply it with a q-tip or something. A bunch of vinegar sloshing around in the lock will not do the circuit board any favors.
When I got into safe work some years ago I noticed the main thing safe guys like to obsess about is batteries. All locksmiths are obsessed with lubricants and which one is the best, safe guys are very particular about batteries. Brand and expiration date mostly. If you want to watch a safe guy’s head explode call them and say you have a warranty issue about a safe lock they installed and make sure there are dollar store batteries in the keypad and claim that they installed those batteries. They will go Tasmanian Devil on you, frothing at the mouth while sputtering and choking out guttural sounds that might remind you of “Energizer” and “Duracell” as they knock everything down around them like a whirling dervish with crossed wires.
These things also matter to your electronic deadbolt: Duracell batteries with an expiration date several years in the future will last a lot longer than some batteries you found covered with a curious sticky substance and cat hair at the back of the bottom shelf at TJ Maxx.
