Sensor Battery Life?

Bought a new multipurpose sensor to put on the front door, and after 13 days - with readings saying 100% - the battery was only reading 1.95 volts and the sensor refused to work.

Replaced with a new, and its working again.

Not sure now, if the sensor is faulty or the battery was a dud one.

It is a the edge of standard wifi reception - although that shouldn’t be a factor as its a different protocol.

Is there something I should be looking for ? - its always read 100%, and I’ve checked the activity and its only been reported open one - on installation (!)

I’m going to try a new battery first, and rule out a dud-one giving false readings.

The sensor will likely drop off 100% right away, but shouldn’t die like that. If you see it again, shoot a note to