I’m over the age of 50. One of the features which some ‘plug-in appliances’ had in my youth, was a rechargeable battery, which allowed them to keep an internal clock running, and therefore to keep track of time, beyond a power failure.
A feature which some ‘smart appliances’, i.e., Internet-connected appliances have today, which seems to be intentional, is the absence of a rechargeable battery. After a power failure, these appliances actually need to set their internal clock, either via a newly established Internet-connection, or via user action. And the main rationale behind this design decision seems to be, ‘The presence of a battery which recharges itself via the A/C may represent some improvement in battery lifespan, but would only represent a slight improvement in lifespan.’ In other words, if such appliances did in fact have such a battery, then instructions would also need to be distributed somewhere, on how to replace them, when they eventually fail. And many appliances’ manufacturers prefer not to broadcast such embarrassing instructions, but rather, to change the design as not to require a battery.
Two appliances which I own that seem to follow this model, are:
- My Dyson Air Purifier / Fan,
- My Security Cams.
In the second case, the trouble has plagued me in the past, that after a very long period of not monitoring the cams, their motion sensor would seem to trip while I’m monitoring them, but would seem to fail to leave any recorded footage, in the app panel where such footage should be found. I’d notice that some amount of storage on the SD Card has been consumed, which corresponded to video recordings, but the list of recordings to be played back would ‘look empty’. Additionally, to reformat the SD Card would succeed.
I finally found out what’s up with that.
After a power failure, the internal clock of these devices would reset itself to some arbitrary point, years in the past. And then, because all the recorded footage would seem more than a few months old, none of it would show up under the ‘recent footage’.
What I need to do once after a power failure is, to access each cam with my app, and then to tap within the GUI of the app, to set the internal clock of the security camera in question. After that, I can play with their settings all I want, and they record reliably.