Batterifying an alarm clock

Question

I bought an alarm clock, like a Neanderthal, in order to get my phone out of my bedroom. I really like the one I got, but I didn't think battery backup was an essential feature when buying it. How foolish of me! Without that guarantee, it's basically useless on work days and I end up keeping my phone near me anyway. For some reason in the place I'm renting we actually get about one power outage every few weeks where the power is off for a split second.

It's too late to return the alarm clock. My ideal would be to allow it to run on battery power. I know I could buy a UPS / battery backup unit, but the cheapest I've found after searching for a few minutes is around $80. For much less than that I could just buy a backup alarm clock. Yet given that in 99% of cases I only need this thing to keep running for 2 seconds without AC power, it feels like a much lower-tech option should be possible.

Is there a cheaper product or, better yet, an easy hack that would solve my problem? Or do I need a new alarm clock?

Answer 1

If the outages are very brief, you might get away with adding a capacitor across the point where the DC is produced (from the AC from the lines).

That would have been easy a few decades ago because all the parts would be obvious (the AC would enter a transformer and then leave at a lower voltage, and then enter a rectifier and leave as DC, and that's where you'd add the capacitor).

But most circuits these days are very tiny and integrated, so that might not be practical.
And the whole unit itself might be factory sealed and unopenable without destroying it.

But if you can get into it, and there are obvious places where wires could be added, then you might be able to do it.

If you include the make and model, and an in-focus closeup of the circuit board (or whatever it has), the folks at Electrical Engineering Stack Exchange might be able to help.

Answer 2

Is there a cheaper product

Yes there is:

This is alarm clock that works only on battery, and not dependent at all on electricity. And it makes lots of noise, had it many years ago and it can awake anyone and anything.

From quick look, on Amazon it costs $18 which is cheaper than what you have/found.

Answer 3

The best alarm, with a built-in battery backup, is ... your cell phone. Lifehack: practice self control. Connect your phone to a charging cable (not a cradle), put it face-down, and don't touch it again until the alarm goes off. Maybe put it far enough from your bed that you can't reach it unless you get out of bed, or put the phone under your alarm clock. Set the phone alarm to be maybe 5 minutes after the alarm clock, so you can still use the new alarm clock but you will have a backup. I find I sleep better knowing that I have a guaranteed, backed-up alarm. If you have an old phone, even better, just leave it plugged in all the time.

As an alternative, consider a voice assistant as an alarm like Amazon Alexa, which will restart after a power outage. (You still have a problem if the power is out when the alarm is supposed to go off, though.) You don't have to pay anything for a voice assistant because you already have one ... on your phone. Unfortunately, setting it face down may impede the voice assistant capabilities, but it may not, or there may be a setting.

If your alarm clock has Bluetooth, you might be able to set up your phone so it plays music through your alarm clock at a given time, which would allow you to leave the phone outside the bedroom and still gain something from its battery back-up capabilities, although that may be less reliable than just using the phone.

One more lifehack: set your alarm to the same time every day, even on weekends and holidays, even if you stayed up late the night before. Then you will start getting up at that time naturally, and you will be a human back-up alarm. You can catch up on sleep the next night, or go back to sleep after you wake up on a non-work day, if you really need the sleep.