Online Full Charge Capacity Modeling of Smartphone Batteries

Full charge capacity (FCC) refers to the amount of energy a battery can hold. It is the fundamental property of smartphone batteries that diminishes as the battery ages and is charged/discharged. We investigate the behavior of smartphone batteries while charging and demonstrate that the battery voltage and charging rate information can together characterize the FCC of a battery. We propose a new method for accurately estimating the FCC without exposing low-level system details or introducing new hardware or system modules. The model enables smartphone users and system designers to debug the performance of the battery. We also design and implement a collaborative battery analytics technique that builds on crowd-sourced battery data. After analyzing one such large data set, we report that 55% of all devices and at least one device in 330 out of 357 unique device models lost some of their FCC. For some models, the median capacity loss exceeded 20% with the inter-quartile range being over 20 pp. a Keywords—Battery, Full Charge Capacity, Charging rate, Voltage.