Apple is offering free battery replacement for some models, see Apple to see if your phone qualifies.
Yes
Apple does not sell replacement parts directly to customers. You could probably get a battery without having it installed from a third-party. That being said, you can find Apple's pricing for iPhone Battery Replacements here and schedule an appointment at with the Genius Bar using the second link :: - https://support.apple.com/iphone/repair/service/battery-power - https://www.apple.com/retail/geniusbar/
do you know if the iphone 6 is included?
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