Change the battery in a lyceum
You have 2 batteries for Your notebook, but how do You exchange them, when You sit in a liceum with no plug in reach?
Not everybody has like I an ASUS UL30A Notebook with 12 hours on battery. A possibility is more run time by a second battery. But how to exchange the battery? The control unit of the 85W solar set makes this possible. Connect the notebook to the control unit. Exchange the nearly empty battery from the notebook with the second battery. Use the notebook connected to the control unit until the control unis shuts off. Then
continue with the second battery in the notebook.
So You can use the electric power from both notebook batteries and the 66 Wh lithium-ion battery in the control unit of the 85W solar set to the best.
When You have only one notebook battery. Use as long as possbile the notebook connected to the 85W control unit, continue with the notebook battery.