This looks more like Apple needed to slow down devices to sell new ones and found a really good excuse for it.
I mean, to all those who might think "well, old phones be old", it's not that simple. The OS was running very smoothly, it's Apple, after all, but then I installed an OS update and after the update everything was slow and painful and took long to load, etc. It was night and day, pre-update: perfection, post-update: laggy as hell.
You can't tell me that this is anything but a way to force users of older models to upgrade.
1. Newer versions of iOS demand more processing power because they do more (or perhaps do it less efficiently).
2. Old batteries can't deliver as much power.
So an old phone will new version of the OS mores slowly than a new one, regardless of the battery situation.
But, if the battery was marginal but hadn't hit the limit before the upgrade, then you get a double whammy
1. The phone simply can't run a more demanding OS as fast as the old one
2. The increased demand pushes the battery over the limit
At some point, the battery was going to age out anyway, so it was only a matter of time until you hit the second issue. But the upgrade made you hit it sonner rather than later.
Does anyone have a citation for this? I know capacity falls, but what fraction of peak current is lost with age? And what fraction with throttling just the CPU to 50% save in total load?
Did your iPad have any problems with spontaneously rebooting?