Stalker battery polarity

For the Stalker V2.1, what is the correct polarity for the CR2032 battery? Should the battery be positive side up or negative side up?

see the wiki :

It’s the standard positive up.

It’s not a too trivial question, but when i checked the schematic and traced the lines i figured out that bottom is GND and top(side) is 3V (pin 14 on DS3231 is 3v VBAT and 13 is GND)

But the darn battery pops out on the smallest vibration :confused: