stsimb@koala3:~$ .bin/batterylog.sh
Charger_Connected=Yes Charging=No Full=Yes Full_Capacity=6216 Remaining_Capacity=6216 Cycle_Count=777

stsimb@koala3:~$ .bin/batterylog.sh
Charger_Connected=No Charging=No Full=Yes Full_Capacity=6216 Remaining_Capacity=6216 Cycle_Count=777

stsimb@koala3:~$ crontab -l
* * * * * ~/.bin/batterylog.sh

stsimb@koala3:~$ cat .bin/batterylog.sh
#!/bin/bash
# mac battery logger
# stsimb jan 2017

# allow only one concurrent instance to run
LOCKFILE="/tmp/${SCRIPT_NAME}.lock"
[ -f ${LOCKFILE} ] && logger "$0 already running......" && echo "Already running..." && exit 1
date >  "${LOCKFILE}"

# vars for log function
PROG="$(basename $0 .sh)"
PID="$$"
LOGFILE="$(dirname $0)/${PROG}.log"

# log to screen and logfile
log() {
    echo "$@"
    echo "$(date) ${HOSTNAME} ${PROG}[${PID}] $@" >> ${LOGFILE}
}

# tempfile
TF="$(mktemp)"

# cleanup trap
cleanup() {
    #log "Cleanup.."
    /bin/rm -f "${TF}"
    /bin/rm -f "${LOCKFILE}"
}
trap cleanup EXIT

# send output to tempfile
/usr/sbin/system_profiler SPPowerDataType > ${TF}

# populate variabled with variables we're interested in
CHARGING="$(grep 'Charging:' ${TF} | head -1 | awk '{print $2}')"
FULLY_CHARGED="$(grep 'Fully Charged:' ${TF} | awk '{print $3}')"
FULL_CAPACITY="$(grep 'Full Charge Capacity' ${TF} | awk '{print $5}')"
REMAINING="$(grep 'Charge Remaining' ${TF} | awk '{print $4}')"
COUNT="$(grep 'Cycle Count:' ${TF} | awk '{print $3}')"
CONNECTED="$(grep 'Connected:' ${TF} | awk '{print $2}')"

TXT="Charger_Connected=${CONNECTED} Charging=${CHARGING} Full=${FULLY_CHARGED} Full_Capacity=${FULL_CAPACITY} Remaining_Capacity=${REMAINING} Cycle_Count=${COUNT}"

log "${TXT}"

# if fully charged, display a notification
if [ "${CONNECTED}x" == "Yesx" ]; then
  if [ "${FULLY_CHARGED}x" == "Yesx" ]; then
    osascript -e "display notification \"Please disconnect the AC Charger.\" with title \"Battery Fully Charged\""
  fi
fi

# delete tempfile -- moved to cleanup trap
#rm -f ${TF}
exit 0