A shell script designed to keep battery log on Android devices

battery_log.sh

CAPACITYVOLTAGE=0
INTERVAL=1

while true; do

PREVVOLTAGE=$CAPACITYVOLTAGE

DATETIME=$(date +'%Y/%m/%d|%H:%M:%S')

CAPACITYVOLTAGE="$(( $(cat /sys/class/power_supply/battery/voltage_now) / 1000 ))"

CAPACITYPERCENT="$(cat /sys/class/power_supply/battery/capacity)"

DISCHARGE="+$(( $CAPACITYVOLTAGE - $PREVVOLTAGE ))"

TEMP="$(( $(cat /sys/class/power_supply/battery/temp) / 10))"

echo "${DATETIME} | ${CAPACITYPERCENT}% | $(echo ${DISCHARGE}|sed -e 's/^+-/-/')mA | ${CAPACITYVOLTAGE}mV | ${TEMP}°C";

sleep $INTERVAL;

done

example_output.txt

2019/06/12|08:19:48 | 25% | +0mA | 3948mV | 38°C
2019/06/12|08:19:49 | 25% | +6mA | 3954mV | 38°C
2019/06/12|08:19:50 | 25% | +0mA | 3954mV | 39°C
2019/06/12|08:19:51 | 25% | -1mA | 3953mV | 39°C
2019/06/12|08:19:53 | 25% | +0mA | 3953mV | 39°C
2019/06/12|08:19:54 | 25% | +0mA | 3953mV | 39°C
2019/06/12|08:19:55 | 25% | +3mA | 3956mV | 39°C
2019/06/12|08:19:56 | 25% | +0mA | 3956mV | 39°C
2019/06/12|08:19:58 | 25% | -1mA | 3955mV | 39°C
2019/06/12|08:19:59 | 25% | +0mA | 3955mV | 39°C
2019/06/12|08:20:00 | 25% | -2mA | 3953mV | 38°C
2019/06/12|08:20:01 | 25% | +0mA | 3953mV | 38°C