Swollen phone battery

[Danny McG]

My wife had this basic Alba (from Argos) smartphone in early 2016.
This was got as a short term replacement until she bought a high spec one again.
After a few week she dropped it and made a big crack in the screen but it still worked OK.

Then new and pricey replacement was got so this Alba was put into the 'odds n ends' drawer.
Tonight I unearthed it while searching for a charger lead, I noticed the back wasn't on so tried to refit it. No chance!
The battery had swollen alarmingly and very bloated in the middle.

Binned immediately, however I'm curious about it, what would cause such a thing to happen to an unused and almost chargeless battery?

 

[Jo Zebedee]

Hasn't this been happening to the new Apple phone too?

 

[Danny McG]

Don't know. Off I go on a trip to the bewildering world of Google to see what can be seen

Edit: back from Google and it seems like it is indeed happening

iPhone 8 Plus: Apple looking into reports of batteries bursting out of phones

 

[tinkerdan]

I have to work with various batteries every day at my job. I'm not an expert by any means. However; most lithium batteries seem to have a large number of similar characteristics that are often frightening and sometimes puzzling and other times disappointing.

Assuming most phones have the chargeable lithium; many of them have to breath and its the the inability to breath properly that usually results in the expansion through the release of gasses. Once a battery is charged you expect it to start to decline from there; however with most batteries, when they sit for a time they begin to re-charge in many environments. This is what often helps support that phenomenon where your flashlight or whatever starts to be filled with leakage from the alkaline batteries. Unevenly charged batteries tend to begin to charge each other until they start to heat up.

So it's possible as the lithium battery sat there it started to charge, which might contribute to the need to out-gas or breathe and the tiny compartment that it is inside of was not enough room for that and perhaps whatever venting the manufacture had in the phone might have been blocked; however more than likely it was just the battery itself failed to allow for that much outgassing. We had one device that we were constantly tossing out rechargeable lithium that were stretching the housing beyond limits.

Also any moisture getting into the battery is very dangerous.

If you aren't using the phone--take the battery out.
If you are using it--check it periodically and replace a battery that bulges immediately--it can be dangerous if you are wearing on your person.

I had this happen to one of my phones--the bulging of the battery-- and it was quite hot--so I probably was at risk at some point.

Added::
Also if the charging circuit or the charger are not correct for that battery that will contribute to this phenomenon because there are tight specifications on how the manufacturer expects that charger to deliver the proper current in the supply that greatly determine both it's usefulness and safety.