Question: how to replace battery on old iphone?
Answer: Replacing the battery via Apple The most convenient and reliable way to replace your iPhone's battery is to do it straight through Apple. Simply swap out your old battery for a brand new one. For iPhone X, XS, XS Max, XR, 11 Pro, 11 Pro Max, and 11 the cost is $69 for an out-of-warranty model not covered by AppleCare+.