Sometimes they’re too sensitive and go off if there’s just a bit of condensation.
That’s been my experience too. Those water alarms are a good idea in theory, but in practice, I’ve had tenants call me in a panic over nothing more than a little humidity. I get wanting to catch leaks early, but if the alarm’s going off every time someone takes a hot shower, it just becomes background noise. People start ignoring it, which kind of defeats the whole point.
I do like your approach with the plumber’s tape and tray. It’s simple, cheap, and you can see at a glance if there’s an issue. I’ve actually gone a step further in some units and used those plastic boot trays you get for muddy shoes—just slide one under the sink or wherever the battery pack sits. They’re wide enough to catch most drips and easy to pull out and check. Not exactly high-tech, but it works.
One thing I’d add: I always tell folks to check under their sinks every couple weeks, especially if they’ve got touchless taps or anything with batteries involved. It’s amazing how fast a slow drip can turn into a warped cabinet or worse. I’ve seen tenants ignore a tiny leak until the wood swells up and then suddenly it’s a much bigger repair bill.
I’m not totally against water alarms, but unless you’re willing to spend for the higher-end models that can distinguish between condensation and an actual leak, I think low-tech solutions like trays and regular checks are just more reliable. Plus, you don’t have to worry about batteries dying or false alarms at 2am.
Touchless faucets are great for hygiene, but they do seem to come with their own set of headaches. I’ve started keeping a roll of plumber’s tape in my toolbox just for these situations. It’s not glamorous, but it saves me from having to replace cabinets down the line.