I'd like an app, whether graphical or command line, that will tell me my laptop battery's charge or discharge rate in watts. The goal is to calculate my needs for a solar panel or other off-grid energy source. It doesn't have to run continuously, typing something on the command line and getting watts usage would be acceptable. I do want it to display watts as that makes my mental gymnastics about power requirements a lot easier. I could probably fudge all the numbers on paper myself but I am lazy and see the purpose of an "app" as to do this sort of work for me.

This article may help get you pointed in the right direction.

http://www.cyberciti.biz/faq/linux-l...s-temperature/

acpi doesn't display watts. gnome-power-statistics looks like the right idea, but I'm running LXDE on Lubuntu, not Gnome. I guess fragmentation of distro efforts is a problem for this sort of thing.

According to the Lubuntu website, Lubuntu shares the "same core system" and repos as Ubuntu.

I would take that to imply that, even if Unity or the Gnome desktop is not installed, there's a good chance that the Gnome libraries are.

I think there's good chance that item would run on Lubuntu.

I haven't tested this, though I might tomorrow if I get a moment to set up a virtual machine, but it could be worth a shot.

Just knowing the charging power will not tell you the total power required by the laptop. You have the charging power, plus the power required to run the laptop plus the losses in the power supply/converters etc. I would just design for the worst case i.e. with the battery totally discharged.