Apple Inc.
Methods for determining and controlling battery expansion

Abstract:

Methods and systems for detecting and compensating for expansion of rechargeable batteries over time. An expansion detector may be coupled to or positioned proximate a rechargeable battery to monitor for expansion thereof. After expansion exceeding a selected threshold is detected, the expansion detector may report the expansion to an associated processing unit. The processing unit may undertake to arrest further rechargeable battery expansion by modifying or changing one or more characteristics of charging and/or discharging circuitry coupled to the rechargeable battery. For example, the processing unit may charge the rechargeable battery at a lower rate or with reduced voltage after detecting expansion.