Ouch that's bad. Mid 60s is approaching the area where the battery won't even last an hour without being plugged in. (There's usually a sharp drop in usable run time around that point - Batteries drop into the 80s fairly fast and then stay there a very long time before dipping into the 70s and 60s)
That being said, ipad batteries are good for 1000 full charge cycles while retaining 80% capacity so that battery must have been abused pretty badly (heat, kept at 100% all the time, etc)
Could technically get it changed at the apple store (don't go 3rd party) but not sure if it's worth it at this point
I reckon this depends on, like I said in my other comment, the iOS version. I have an iPhone 6s with 63% health (original battery since 2016), and battery life is superb, almost matching like-new battery life with light use.
I did not even notice a difference when browsing with full brightness and LTE! That would obliterate a 100% health iPhone 6s on iOS 15, I reckon it wouldn’t even get 2 hours. I was totally impressed, I extrapolated it and I would’ve gotten about 5 hours on screen-on time at 100% brightness and LTE web browsing. I typically quote 6.5-hours of web browsing on LTE, but that’s closer to 50% brightness. I don’t use it at full brightness unless I need to, but frankly, I was impressed by that. Even if I can’t get 5 and get 4.5 hours, that’s still insane. I tried an iPhone 6s on iOS 13 and 94% health and I got 1.5 hours of screen-on time with 66% remaining... on Airplane Mode, and 0% brightness. Appalling. My 6s on iOS 10 obliterates that number even with full brightness and LTE.
The only activity in which I noticed a huge power draw was 4K filming with LTE and full brightness. The battery meter dropped astonishingly quickly, decreasing about 3 to 4% after a one-minute video. That would give about 25 minutes of full brightness, LTE filming. That has never been any iPhone’s strong suit (especially not 4.7-inch iPhones and earlier), but I do reckon it would be better with a new battery. How much, that I do not know.
Regarding iPads and capacity: I know that it depends on usage. I know that it depends on a million factors (charge patterns, temperature, and a long list of etc that you already know), but in my experience - and most importantly, unlike iPhones - I’ve never had a single iPad reach that spec. Once again, yes, it depends on a million factors, but the vast majority of the iPhones I’ve had - if not all - (and the ones I’ve been able to check) were well within spec, even when usage and charging patterns varied wildly. iPads... not at all. My iPad 4 had 77% after only 530 cycles, and my 9.7-inch iPad Pro has 84% after about 650. A family member’s iPad Mini 1 now has over 1000 (1050 I think) and stands at about 70% health. Check the OP’s Air 2: 65% health after 832 cycles. Yes, battery age is a factor (and as iPads have better battery life, it takes longer to get to very high amounts of cycles), but iPhones retain health a lot better! My iPhone 5c has over 1000 cycles (must be close to 1100) and it is above 80% (twice over spec), my iPhone 5s on iOS 8.2 (with a broken screen, pain) has about 800 cycles with 85% health even after almost 8 years (it is now unused in a drawer). So, even comparably old iPhones retain health better. I asked here about that once, three years ago, but I didn’t get many high cycles replies:
https://forums.macrumors.com/thread...share-your-battery-health-and-cycles.2170724/
@rui no onna do you still have any of the iPads you mentioned back then? If you can, may you please give an update on cycles and health?
PD: Admittedly, as iPhones are more popular, my sample size on iPads is a lot smaller. Regardless, like I said, I haven’t seen any iPhone off-spec, and I haven’t seen any iPad within spec. Maybe I need a larger sample size, maybe iPads’ battery decays faster with age (like I said, in my experience, iPhones retain health a lot better even after the same amount of years as iPhones), I frankly do not know the reason for that.