upower -i /org/freedesktop/UPower/devices/battery_BAT0 will give you information about your laptop battery.
homer@neo:~/Documents$ upower -i /org/freedesktop/UPower/devices/battery_BAT0 native-path: /sys/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/device:0c/PNP0C0A:00/power_supply/BAT0 vendor: PANASONIC model: Li_Ion_4000mA serial: 0000 power supply: yes updated: Sun Sep 29 02:39:34 2013 (3 seconds ago) has history: yes has statistics: yes battery present: yes rechargeable: yes state: discharging energy: 27.2484 Wh energy-empty: 0 Wh energy-full: 45.414 Wh energy-full-design: 47.52 Wh energy-rate: 15.984 W voltage: 10.862 V time to empty: 1.7 hours percentage: 60% capacity: 95.5682% technology: lithium-ion History (charge): 1380386343 60.000 discharging History (rate): 1380386374 15.984 discharging 1380386343 16.351 discharging 1380386312 16.243 discharging 1380386281 17.528 discharging
Use grep with this command to see if you are connected to the power or the laptop is using the battery.
homer@neo:~/Documents$ upower -i /org/freedesktop/UPower/devices/battery_BAT0 | grep state: state: discharging
You may also use the acpi command to get information about your laptop battery.
homer@neo:~/Documents$ acpi Battery 0: Discharging, 52%, 01:27:04 remaining
These are very useful commands to know when you are using a laptop with Linux. Making it very easy to get information about your laptop hardware.
Here is a way to see if the laptop is open or shut.
homer@neo:~/Documents$ cat /proc/acpi/button/lid/LID0/state state: open
I guess this could be useful if you are connecting to the laptop with SSH.