My T420's battery is detected by acpi, and it's in the "Unknown" state that it usually is when the battery is above the charging threshold but below 100%, but whenever I unplug power, the whole thing shuts off as if the battery weren't plugged in at all. Is there anything I can do to test it more robustly to see what about it is hosed if anything is? I have coreboot installed, is there any reason that would fuck with it? The batter was working just fine as of last week, I don't know what changed.
$ acpi -V
Battery 0: Unknown, 99%
Battery 0: design capacity 8424 mAh, last full capacity 8425 mAh = 100%
Adapter 0: on-line[/code[