chroot

root@openthinklabs:/home/pi# mount /dev/sda2 /media
root@openthinklabs:/home/pi# cd /media
root@openthinklabs:/mnt# mount --bind /dev dev/
root@openthinklabs:/mnt# mount --bind /sys sys/
root@openthinklabs:/mnt# mount --bind /proc proc/
root@openthinklabs:/mnt# mount --bind /dev/pts dev/pts
root@openthinklabs:/mnt# chroot . bin/bash
root@openthinklabs:/# update-grub

LXDE

 ...

Referensi

1. Change LXDE Battery Monitor in DEBIAN, https://blog.desdelinux.net/en/change-lxde-battery-monitor-in-debian/
   
2. How to activate a "low battery" alert in LXDE, https://blog.desdelinux.net/en/how-to-activate-a-low-battery-alert-in-lxde/