When iPads, mobile phones and laptops, get to a certain age, their batteries start to fail.
iPads and indeed all modern devices such as laptops, mobile phones etc use lithium ion batteries because of their performance benefits.
This is what a normal, health iPad battery looks like:
However, the dark side of lithium ion batteries is that they can swell significantly as can been seen in this image:
I tried to find a simple, non technical explanation as to why batteries wrinkle but I'm afraid this is the best I could do:
In general, a swollen battery occurs when the battery’s cells are overcharged, as lithium-ion batteries “react unfavourably to overcharging,” according to Don Sadoway, Professor of Materials Chemistry at MIT. As Professor Sadoway explained to Electronics Weekly:
"There are strict limits on how much current can be put through a lithium-ion cell. During normal charging, you never see metallic lithium, which is inherently unstable. But during overcharging, the lithium builds up faster than it can dissipate. The result is that metallic lithium plates up on the anode. At the same time, the cathode becomes an oxidizing agent and loses stability."
This faulty iPad battery was discovered when the iPad was in our repair workshop to have its digitiser replaced. As a result of the battery swelling up so much, the replacement digitiser could not be re-located correctly thus stopping the full adhesion of the replacement digitiser.
The only solution was to replace the battery while the digitiser had been removed from the iPad.
Happily the iPad has a new lease of life and is back to normal daily use.
Please note that as with all batteries but particularly lithium ion batteries, please dispose of them correctly and do not just put them into the normal waste.