Comment 6 for bug 674213

I'm having the same issue as Matt and Jnelson11.

I running a Lenovo T-420 and Mint (Katya) w/ 2.6.38-8-generic kernel. I get up to eight hours of unplugged operation between charges. I don't think it's a buggy battery. According to acpi:

tim@cthulhu:~$ /usr/bin/acpi -V
Battery 0: Discharging, 50%, 03:04:26 remaining
Battery 0: design capacity 8538 mAh, last full capacity 8517 mAh = 99%
Adapter 0: off-line
Thermal 0: ok, 43.0 degrees C
Thermal 0: trip point 0 switches to mode critical at temperature 98.0 degrees C
Cooling 0: LCD 4 of 15
Cooling 1: Processor 0 of 10
Cooling 2: Processor 0 of 10
Cooling 3: Processor 0 of 10
Cooling 4: Processor 0 of 10

After re-waking from a suspend, I get a red battery icon regardless of how well charged the battery is. Fortunately the power manager does not shut down my laptop. Even though the battery icon is red, clicking the indicator will display a battery life that seems accurate.

In a nutshell, it seems that the percentage remaining is calculated incorrectly, causing the indicator color to show critical even when acpi confirms the remaining battery life is adequate.