Old forum members probably already knew this from previous old thread ->
Y.A.R.A. (Yet Another Rotten Alkaline)
Yesterday, took out my Fluke 87V, turned on, and the screen showed its low on battery, while in my hand, I turned if off, and then did shake the DMM abit, turned it on again, the low battery indicator was gone, so the battery was still providing enough voltage.
Intuitively I thought must be loose connection on the 9V terminal, opened the Fluke 87V back cover, and when I try to detach the 9V terminal with sort of peeling movement, the whole negative terminal was sort of torn and broke into pieces, and revealed its heavily corroded.
As you can see, I have habit of marking the battery's installation date using marker, its just < 3 years and the factory expiration date still on Feb 2021.
The meter all this time was stored in stable room temperature, and never used outdoor in harsh environment. Yes, the battery is genuine and imo from quite reputable brand.
Attached photo below, see for your self.
Always thought and read a lot on such statements ... "Oh ... 9V alkaline cell don't leak like ordinary cylinder alkaline cells do" ...
... that claim is WRONG !
The leak apparently was through one of terminal, it sorts of oozing/venting out corrosive gas and corroded the negative terminal, as the photo, the other terminal (+) is still in very good shape.
Moral story, check ... check ... and diligently check especially your expensive T&M gears that are powered using alkaline cell, even its non cylinder type like this 9V box type.
Hope this helps, at least to motivate you to check your gears ... NOW !
EDIT : Update at ->
Post #13 photos of the battery's internal.