Anyone know why do my motion sensor LED closet lights turn on randomly at night and how do I stop it?

I went through this in my hallway closet too and mine always flicked on around 2 a.m. with the door shut. It turned out the overnight HVAC cycle pushed a slow draft through the door gap and the PIR saw that moving temperature change as motion. Lowering sensitivity and recharging did nothing and taping a sleeve didn't help either.

What finally worked was two quick tweaks. I rotated each light so the sensor faces a solid surface like the back wall or a shelf, not the door or hanging clothes. Then I masked the outer edge of the PIR lens with a thin crescent of black electrical tape to narrow the field of view. Diffuser tape did not help since PIR sees infrared, not visible light, so you need opaque tape or foil. I also added thin weatherstrip on the door stop to kill the draft. After that I stopped getting ghost activations.

If yours still misbehave, I replaced one with Gritin 10.2inch and it's been calmer in the same closet. The four modes let me run a true night motion setting and the five brightness levels keep it low so it isn't blinding when it does trigger. Only minor gripe is it's a touch longer than my old bars, but it's been solid.

Quick checklist that helped me finish the job fast. Aim sensors at a wall or floor. Mask the lens to narrow the view instead of covering the whole thing. Add a sliver of door weatherstrip to stop the draft. Keep the auto off time short to save battery if it ever does trip.

Nighttime triggers often come from slow convection after the system cycles off.

Warm air drifts along the ceiling and down the walls and the sensor sees that.

Putting the light lower in the closet made a big difference for me.

I stuck it just above the baseboard on the side wall and aimed it at the floor so it only sees legs when the door opens.

If you want to confirm that drafts are the culprit, run the fan in circulate for one night.

If the random activations change or stop, it is airflow.

Then you know to seal the gap with a sweep or weatherstrip and keep the sensor looking at a solid surface.

Before giving up try a quick test to find the trigger path. Tape a thin strip of tissue paper over the door gap inside the closet and close the door. If you find it moved in the morning the sensor probably saw that same draft. Then mask the lens on that side with a tiny wedge of opaque tape and add a narrow door sweep so the pressure change does not push air past the crack.

If the tissue stays still look for a heat source change instead. Water heater on a timer, attic hatch above, even a charger in the closet can create a gentle plume. Shift the light so the sensor stares at a blank wall and give it a short auto off setting so any rare false trip is brief. That combination usually tames them.

Often the easiest answer is placement. If the sensor can see the door crack or any hanging fabric it will eventually catch a little temperature ripple. Mount the bars farther back on the side walls and tilt them so the sensor points at a solid surface or the floor.

A thin door sweep or stick on weatherstrip around the strike side helps too. I actually added two small felt bumpers on the door stop so it closes tighter. No more ghost activations and I did not have to return anything.

hunch about air moving clothes is probably right but sometimes the hangers only twitch a millimeter and that is enough. I actually had to immobilize the row of shirts. Two zip ties around the rod with a small gap creates a corral so the hangers cannot slide and sway. can also clip a couple of hangers together near the hook to dampen motion.

Then point the sensor down the wall rather than across the rod. I left a tiny sliver of black tape on the outer edge of the lens to keep it from seeing the door gap. Works great.

Two things woke mine up at night... Tiny insects and tiny drafts. Closets are spider heaven and a little web across the PIR lens will trip it now and then. I popped the light off blew the lens out with canned air, wiped it, and vacuumed the upper corners of the closet. Tiny spider inside the Fresnel. Gone and no more random pings.

If that is not it aim the sensor downward so it sees the floor instead of the door gap and clothes. Opaque tape works to narrow the view. A skinny crescent along one edge is enough. Diffuser tape will not help since PIR sees heat not brightness.

I install alarm PIRs for a living and this is a classic case of field of view being too wide for a small space. Those little bar lights have a coarse Fresnel lens and they happily trip on drafts through the door gap. You do not want to cover the whole sensor because then it will not work when you need it.

Make a tiny hood so the sensor only sees straight ahead. Cut a short piece of drinking straw or a bit of heat shrink about as long as the lens is thick, and tape it around the sensor to create a tunnel. It narrows the acceptance cone a lot and you keep good range when the door opens. Cheap fix and it works.

Vibration fooled the PIR when the shelf buzzed as the air handler started since sensor movement also looks like motion. Mount it to wood, add putty to dampen shake, and tighten the door latch with felt dots if it taps at night.

A timed hot water line warmed the wall and sent a slow heat plume past the PIR that looked like motion. Facing it toward a cooler wall and blocking the warm side with a small baffle or opaque tape stopped the false triggers.