How long does the battery last per charge?

The listing does not state a runtime. Expect shorter intervals in high-traffic spots where the sensor triggers often, and longer in closets used a few times a day. Keep the USB cable handy and recharge when the light dims.

It is a small accent and task light, not a room light. It works best within a meter or so of what you are lighting, such as a shelf, a closet rod or a stair tread.

What is the difference between the single and the two-pack linkage models?

The single model is one light with one magnetic disk. The two-light set is described as a linkage configuration, so the pair is meant to work together in one area. Check the box contents for how many mounts and cables come with each.

A magnetic disk attaches to the wall or shelf, and the light holds to it magnetically. That lets you pull the light off to recharge without removing the mount.

Does the sensor work in daylight?

The listing describes a human body motion sensor with automatic shutoff after inactivity. It does not specify a daylight threshold, so assume it triggers whenever it detects movement.

Is it safe in a bathroom or kitchen?

It runs at 36V or less and is USB charged, which is low voltage. The listing gives no water-resistance rating, so keep it away from splashes and steam.