Computing battery lifetime distributions

 

Dr. Lucia Cloth (University of Twente)

 

Abstract:

 

The usage of mobile devices like cell phones, navigation systems, or
laptop computers, is limited by the lifetime of the included
batteries. This lifetimes depends naturally on the rate at which
energy is consumed, however, it also depends on the usage pattern of
the battery. Continuous drawing of a high current results in an
excessive drop of residual capacity. However, during intervals with no
or very small currents, batteries do recover to a certain extend.  We
model this complex behaviour with an inhomogeneous Markov reward
model, thereby following the approach of the so-called Kinetic battery
Model (KiBaM).  The state-dependent reward rates thereby correspond to
the power consumption of the attached device and to the available
charge, respectively. We develop a tailored numerical algorithm for
the computation of the distribution of the consumed energy and show
how different workload patterns influence the overall lifetime of a
battery.