confused PIR sensor due to dead battery

[manjh]

Just a word of warning, since this took me several hours to tackle and it might save you some time.

I use a cheap Chinese PIR sensor to detect movement in the kitchen and switch on the lights.
The sensor is powered by a 9V battery block. When the battery is low, the sensor should give a visible warning.

My sensor/dimmer setup was behaving very strange, sometimes giving a signal, sometimes not.
The "low battery" warning was not given, and I did not have any clue since the cell was relatively new.

After checking everything, I decided to remove the battery and measure voltage.
Could not believe the reading: 2.37V! I have never seen a 9V block battery this low.
Apparently this extremely low voltage threw off the low-battery warning...

[SweetPants]

This is a known issue and handled many times before and is warned about

Verstuurd vanaf mijn SM-G903F met Tapatalk