Abstract
In real Wireless Sensor Networks applications is
very important to take into account the current battery state of
health. A parameter that can provide significant information of
the battery state is its internal resistance. For estimating the
internal resistance, we assume a simple battery model composed
of a source voltage and an internal resistor. This model is suitable
for being implemented in low-cost motes with very limited
computational capabilities. The procedure of estimating this
value involves the acquisition of battery voltages and drained
currents during the execution of a typical WSN application. We
take advantage of the run-time execution of the program for
measuring several voltages with different currents. Thus, the
program measures the voltage and current when the system is in
high power state (the radio is on) and in low power state (the
radio is off). The method has been validated with real
experiments with Telosb motes providing good results at
different environmental conditions.
