My 2 Contact Sensors on my mailbox batteries lasted only 5 months.
The original CR1632 Battery has 130 mAh . I decided to hard wire the sensors to CR123A batteries with 1500mAh .
They should least 10 times as long as the original CR1632 . I should get least 3+ years out of them .
I might do the same to other door contact sensors if I can find a small enough project box to mount the battery in .
Here are my 2 sensors
1 for the Mailbox and the 2nd for the Newpaper box.
I mounted the battery box behind the sensors under the mailbox .
I also measured the amperage draw of the contact sensor .
I found that it draws about 14 mA when there is a state change ( Contact open or closed) for less than 0.5 sec.
They draw only 1.6 Microampere µA when not broadcasting a state change . It draws the same if the contact is open or closed.
I am not sure what the draw is when it broadcast a heartbeat message or how often it broadcasts this message . I assume it would be the same 14 mA .
Normal operation amperage draw
Amperage draw when state changes