I wrote a simple script to log the battery information. It doesn't write when the battery is full and also was full in the last check, to avoid filling the log with useless information. I have it set up to run every minute with crontab.
I'm posting it here in case it's useful to anyone.
#!/bin/bash
BATT_DIR=/sys/class/power_supply/battery
LOG_FILE=/tmp/battlog.csv
OLD_STATUS=/tmp/status
if [ ! -f "$OLD_STATUS" ]
then
echo -n "No_Status" > $OLD_STATUS
fi
if [ $(cat $BATT_DIR/status) != "Full" ] || [ $(cat $OLD_STATUS) != $(cat $BATT_DIR/status) ]
then
echo -n $(date +"%F %R") >> $LOG_FILE
echo -n ";" >> $LOG_FILE
echo -n $(cat $BATT_DIR/capacity) >> $LOG_FILE
echo -n ";" >> $LOG_FILE
echo -n $(cat $BATT_DIR/status) >> $LOG_FILE
echo -n ";" >> $LOG_FILE
echo -n $(cat $BATT_DIR/voltage_now) >> $LOG_FILE
echo -n ";" >> $LOG_FILE
echo $(cat $BATT_DIR/current_now) >> $LOG_FILE
fi
cat $BATT_DIR/status > $OLD_STATUS
Cheers!