<i>Edit: For the sake of completeness, the deleted parent suggested that iPhones are unable to be opened because they&#x27;re glued up, and doing so (to reseat the battery) would void the warranty</i><p>Nope.<p>(Former) Apple Retail &#x27;Genius&#x27; here. iPhones are trivial to open up to get to the battery, provided the right equipment (tore screwdriver and suction cup + grip), and disconnecting the battery is just a simple tab&#x2F;plug to lift up.<p>Because this isn&#x27;t a &#x27;modification&#x27; (Apple warranty forbids unauthorised third party modifications) and is exactly what they would do in Apple Store anyway, you&#x27;re safe to do this yourself without voiding your warranty, as long as you know what you&#x27;re doing.