Why Do Blister Packs With Button Cells Need Air Vents?

[Boris_yo]

Ordered these from China and noticed blister pack has air vents (see attached picture). Why do button cell batteries need these? I didn't notice same vents on AA battery backs.

[Rerouter]

i would assume its more for the packaging, as the difference from sea-level especially by airmail could crinkle or partly break the seal on the packaging otherwise

[SeanB]

It is for the sealing of the cells into the packaging, as this is done with a heating pad that presses down onto a sheet of cardboard that in turn is pressed down onto the plastic blisters in a jig. No air holes means you get collapsed blisters when you remove the packaged unit from the jig as the air inside the blisters cools rapidly and the card is coated with a thermoplastic film that melts to seal to the blister PVC. Expensive for the tooling ( or you make them in wood) and the ejector pins are very expensive, and last only for around 10k of operations.

[gibbled]

I always thought those holes were for probing to check if the battery still holds a charge without opening the package.

[Psi]

I thought they were just a hole to use your finger and tear the cardboard away with.

[Boris_yo]

I always thought those holes were for probing to check if the battery still holds a charge without opening the package.

Is doing this possible without opening the package? How can this be done? I can only assume this can be done with multimeter.

[orbiter]

I always thought those holes were for probing to check if the battery still holds a charge without opening the package.

You'd have to have a pretty good probe to get through that hole & then round to negative side of the battery to complete the measurement

[Fsck]

I thought they were just a hole to use your finger and tear the cardboard away with.

ditto.

[gibbled]

Lol about the pretty good probes, my blister packs are also perforated on the blister side.  Very probe friendly...

[Razor512]

I feel they are for probing also,. They came in handy at the store when I had to buy a replacement battery for a motherboard, and I did not want to wait for a shipment.

Many stores do not sell those batteries very often and will have lots of old and to get one that was at the proper voltage I have to test about 4 different batteries. (Most were in the upper 2V but I was finally able to get one that was at 3.26V which is where cr2032 batteries are at when they are mostly fresh and not shitting on a shelf since the paleolithic age)

[amyk]

Lol about the pretty good probes, my blister packs are also perforated on the blister side.  Very probe friendly...

Those are definitely for probing.

[G7PSK]

I also thought that they were to ease the removal from the packaging, but my experience is that you still need industrial power tools to complete the removal.