In times of 2-21 to 2-25, gnome-power-manager maintained an big fat elaborate cache of power devices and combination devices which was populated by HAL. This allowed us to have “virtual” devices such as multiple composite laptop batteries. This abstraction sucked and made some horrible assumptions about devices. And it was slow.
These virtual batteries were used for policy, and generally multiple batteries sort-of-just-worked, with a few random things happening when the engine virtual layer fell down. I couldn’t test virtual devices, as my Toshiba only had one battery with no expansion available, so I relied on random patches from strangers.
Fast forward to last-week/2-26/DeviceKit. Now gnome-power-manager had a very small new ‘thin’ engine with all the devices supplied by DeviceKit-power. Batteries, on the whole were a whole lot more predictable, and the architecture was at last fairly sane. I had now got a nice shiny Thinkpad, still with only one battery, but with extra space for another. But wait, I know what you are thinking; Thin engine means no composite devices, which makes people with multiple battery laptops sad.
Fast forward to this weekend/2-27/DeviceKit. My ultrabay battery arrived in the post from the US (with customs charge, bahh) which I plugged in to the Thinkpad. Much hacking was done, and a few changes (related to empty batteries) went into DeviceKit-power and a few changes went into gnome-power-manager. Now we have a composite store with a thin engine, so the best of both worlds.
So, long story, short: if you have laptop with multiple batteries and your experience with gnome-power-manager sucks, update to git versions of DeviceKit-power and gnome-power-manager. I’ll be making releases later this week, and backporting to stable once it’s had some testing.