Franklin T9 battery charging limiter script

#!/bin/sh
TARGETV=410
while [ true ];  do
  VOLTAGE=`cut -c1-3 /sys/class/power_supply/fuelgauge/voltage_now`
  VDIFF=`expr $VOLTAGE - $TARGETV`
  if [ "$VDIFF" -gt 10 ]; then
    CUR=133
  elif [ "$VDIFF" -gt 5 ]; then
    CUR=167
  elif [ "$VDIFF" -gt 0 ]; then
    CUR=200
  elif [ "$VDIFF" -gt -5 ]; then
    CUR=233
  elif [ "$VDIFF" -gt -10 ]; then
    CUR=267
  else
    CUR=500
  fi
  read LAST < /sys/class/power_supply/battery/input_current_max
  if [ "$LAST" != "$CUR" ]; then
    echo $CUR >/sys/class/power_supply/battery/input_current_max
  fi
  read TEMP < /sys/devices/virtual/thermal/thermal_zone0/temp
  echo V:$VOLTAGE  C:$CUR T:$TEMP
  sleep 60
done >/var/log/bms.log &