Apple's recently changed the terms of its AppleCare+ extended warranty program. Now, no matter what iOS or OSX device you own (yes, even the Watch), Apple will replace the battery as soon as it hits 80 percent health. That's up 30 points from the previous 50 percent threshold for iOS devices. What's more, Mac batteries used to only be covered for manufacturing defects, not normal performance degradation. So basically anything with an Apple logo will get a new battery once the old one loses 20 percent of its capacity. The policy kicks in immediately for devices purchased after April 10th of this year.