Battery state-of-health estimation for mobile devices

Abstract

Insu cient support of electric current sensing on commodity mobile devices leads to inaccurate estimation of their ba ery's stateof-health (SoH), which, in turn, shuts them o unexpectedly and accelerates their ba ery fading. In this paper, we design V-BASH, a new ba ery SoH estimation method based only on their voltages and is compatible to commodity mobile devices. V-BASH is inspired by the physical phenomenon that the relaxing ba ery voltages correlate to ba ery SoH. Moreover, it is enabled on mobile devices with a common usage pa ern of most users frequently taking a long time to charge their devices. e design of V-BASH is guided by 2, 781 empirically collected relaxing voltage traces with 19 mobile device ba eries. We evaluate V-BASH using both laboratory experiments and eld tests on mobile devices, showing a <6% error in SoH estimation. CCS CONCEPTS •Computer systems organization →Embedded so ware;

A State of Health Estimation Method for Lithium-Ion Batteries Based on Voltage Relaxation Model

“…In addition to the aforementioned SOH estimation methods based on the battery capacity and impedance estimation, which generally need to be implemented under a certain dynamic working condition, a novel SOH estimation method which utilizes the resting process after charging or discharging, that is, the relaxation voltage process, has been proposed in recent years. Various researchers have proved that the relaxation process has relationships with the SOH of battery, and the terminal voltage of the battery during relaxation process, namely the relaxation voltage, could be used to estimate the battery SOH [25][26][27][28][29]. Baghdadi et al [25] measured the relaxation voltage after fully charged and 30 min of rest and found a linear dependence between that value and the capacity value.…”

“…An estimation method was then established based on that relationship. Similarly, He et al [26] and Qin et al [27] used the relaxation voltage value after fully charged and studied the relationship between the value and capacity of the battery after different aging cycles. Kai et al [28] utilized a period time of the relaxation voltage, that is, the relaxation voltage curve as the research subject.…”

An Incremental Voltage Difference Based Technique for Online State of Health Estimation of Li-ion Batteries

“…There are few novel methods reported in the literature where some kind of special arrangements are made to estimate the SOH [22][23][24] . In 22 , the response of an AC excitation current is processed using the nonlinear frequency response analysis (NFRA) technique to estimate the capacity fade due to the loss of active material.…”

“…The change in the circuit parameters indicates the battery degradation. Resting period battery voltage after the complete charging is used to estimate SOH in 24 .…”

“…2. Complete charging or discharging battery data is needed for few cases 16,24 . Under practical uses, the batteries are normally charged and discharged partially, and the extent of charging or discharging is quite random.…”