Battery life starts at 2:30 hrs (99%), but less than 1 minute later is only 1:30 hrs (99%)
- by zondu
After searching this and other forums, I haven't seen this same issue listed anywhere for Ubuntu 12.
Prior to installing Ubuntu 12.10, my Netbook (Acer AspireOne D250, SATA HDD) was consistently getting 2:30-3 hrs battery life under Windows XP Home, SP3. However, immediately after installing Ubuntu 12.10, the battery life starts out at 2:30 hrs (99%), but less than 1 minute later suddenly drops to 1:30 hrs (99%), which seems very odd. It could be a complete coincidence that the battery is suddenly flaky at the exact same moment that Ubuntu 12.10 was installed, but that doesn't seem likely.
I'm a newbie to Ubuntu, so I don't have much experience tweaking/trouble-shooting yet. Here's what I've tried so far:
enabled laptop mode (sudo su, then echo 5 /proc/sys/vm/laptop_mode) and checked that it is running when the A/C adapter is unplugged, but it doesn't seem to have made any noticeable difference in battery life,
installed Jupiter, but it didn't work and messed up the system, so I had to uninstall it,
disabled bluetooth (wifi is still on b/c it is necessary), set the screen to lowest brightness, etc.,
run through at least 1 full power cycle (running until the netbook shut itself off due to critical battery) and have been using it normally (sometimes plugged in, often unplugged until the battery gets very low) for a week since installing Ubuntu 12.10.
installed powertop, but have no idea how to interpret its results.
Here are the results of acpi -b:
w/ A/C adapter: Battery 0: Full, 100%
immediately after unplugging: Battery 0: Discharging, 99%, 02:30:20 remaining
1 minute after unplugging: Battery 0: Discharging, 99%, 01:37:49 remaining
2-3 minutes after unplugging: Battery 0: Discharging, 95%, 01:33:01 remaining
10 minutes after unplugging: Battery 0: Discharging, 85%, 01:13:38 remaining
Results of cat /sys/class/power_supply/BAT0/uevent:
w/ A/C adapter:
POWER_SUPPLY_NAME=BAT0
POWER_SUPPLY_STATUS=Full
POWER_SUPPLY_PRESENT=1
POWER_SUPPLY_TECHNOLOGY=Li-ion
POWER_SUPPLY_CYCLE_COUNT=0
POWER_SUPPLY_VOLTAGE_MIN_DESIGN=10800000
POWER_SUPPLY_VOLTAGE_NOW=12136000
POWER_SUPPLY_CURRENT_NOW=773000
POWER_SUPPLY_CHARGE_FULL_DESIGN=4500000
POWER_SUPPLY_CHARGE_FULL=1956000
POWER_SUPPLY_CHARGE_NOW=1956000
POWER_SUPPLY_MODEL_NAME=UM08B32
POWER_SUPPLY_MANUFACTURER=SANYO
POWER_SUPPLY_SERIAL_NUMBER=
immediately after unplugging:
POWER_SUPPLY_NAME=BAT0
POWER_SUPPLY_STATUS=Discharging
POWER_SUPPLY_PRESENT=1
POWER_SUPPLY_TECHNOLOGY=Li-ion
POWER_SUPPLY_CYCLE_COUNT=0
POWER_SUPPLY_VOLTAGE_MIN_DESIGN=10800000
POWER_SUPPLY_VOLTAGE_NOW=11886000
POWER_SUPPLY_CURRENT_NOW=773000
POWER_SUPPLY_CHARGE_FULL_DESIGN=4500000
POWER_SUPPLY_CHARGE_FULL=1956000
POWER_SUPPLY_CHARGE_NOW=1937000
POWER_SUPPLY_MODEL_NAME=UM08B32
POWER_SUPPLY_MANUFACTURER=SANYO
POWER_SUPPLY_SERIAL_NUMBER=
1 minute later:
POWER_SUPPLY_NAME=BAT0
POWER_SUPPLY_STATUS=Discharging
POWER_SUPPLY_PRESENT=1
POWER_SUPPLY_TECHNOLOGY=Li-ion
POWER_SUPPLY_CYCLE_COUNT=0
POWER_SUPPLY_VOLTAGE_MIN_DESIGN=10800000
POWER_SUPPLY_VOLTAGE_NOW=11728000
POWER_SUPPLY_CURRENT_NOW=1174000
POWER_SUPPLY_CHARGE_FULL_DESIGN=4500000
POWER_SUPPLY_CHARGE_FULL=1956000
POWER_SUPPLY_CHARGE_NOW=1937000
POWER_SUPPLY_MODEL_NAME=UM08B32
POWER_SUPPLY_MANUFACTURER=SANYO
POWER_SUPPLY_SERIAL_NUMBER=
2-3 minutes later:
POWER_SUPPLY_NAME=BAT0
POWER_SUPPLY_STATUS=Discharging
POWER_SUPPLY_PRESENT=1
POWER_SUPPLY_TECHNOLOGY=Li-ion
POWER_SUPPLY_CYCLE_COUNT=0
POWER_SUPPLY_VOLTAGE_MIN_DESIGN=10800000
POWER_SUPPLY_VOLTAGE_NOW=11583000
POWER_SUPPLY_CURRENT_NOW=1209000
POWER_SUPPLY_CHARGE_FULL_DESIGN=4500000
POWER_SUPPLY_CHARGE_FULL=1956000
POWER_SUPPLY_CHARGE_NOW=1878000
POWER_SUPPLY_MODEL_NAME=UM08B32
POWER_SUPPLY_MANUFACTURER=SANYO
POWER_SUPPLY_SERIAL_NUMBER=
10 minutes later:
POWER_SUPPLY_NAME=BAT0
POWER_SUPPLY_STATUS=Discharging
POWER_SUPPLY_PRESENT=1
POWER_SUPPLY_TECHNOLOGY=Li-ion
POWER_SUPPLY_CYCLE_COUNT=0
POWER_SUPPLY_VOLTAGE_MIN_DESIGN=10800000
POWER_SUPPLY_VOLTAGE_NOW=11230000
POWER_SUPPLY_CURRENT_NOW=1239000
POWER_SUPPLY_CHARGE_FULL_DESIGN=4500000
POWER_SUPPLY_CHARGE_FULL=1956000
POWER_SUPPLY_CHARGE_NOW=1644000
POWER_SUPPLY_MODEL_NAME=UM08B32
POWER_SUPPLY_MANUFACTURER=SANYO
POWER_SUPPLY_SERIAL_NUMBER=
Results of upower -i /org/freedesktop/UPower/devices/battery_BAT0:
w/ A/C adapter:
native-path: /sys/devices/LNXSYSTM:00/device:00/PNP0A08:00/device:02/PNP0C0A:00/power_supply/BAT0
vendor: SANYO
model: UM08B32
power supply: yes
updated: Tue Nov 27 15:24:58 2012 (823 seconds ago)
has history: yes
has statistics: yes
battery
present: yes
rechargeable: yes
state: fully-charged
energy: 21.1248 Wh
energy-empty: 0 Wh
energy-full: 21.1248 Wh
energy-full-design: 48.6 Wh
energy-rate: 8.3484 W
voltage: 12.173 V
percentage: 100%
capacity: 43.4667%
technology: lithium-ion
immediately after unplugging:
native-path: /sys/devices/LNXSYSTM:00/device:00/PNP0A08:00/device:02/PNP0C0A:00/power_supply/BAT0
vendor: SANYO
model: UM08B32
power supply: yes
updated: Tue Nov 27 15:41:25 2012 (1 seconds ago)
has history: yes
has statistics: yes
battery
present: yes
rechargeable: yes
state: discharging
energy: 20.9196 Wh
energy-empty: 0 Wh
energy-full: 21.1248 Wh
energy-full-design: 48.6 Wh
energy-rate: 8.3484 W
voltage: 11.86 V
time to empty: 2.5 hours
percentage: 99.0286%
capacity: 43.4667%
technology: lithium-ion
History (charge):
1354023683 99.029 discharging
1 minute later:
native-path: /sys/devices/LNXSYSTM:00/device:00/PNP0A08:00/device:02/PNP0C0A:00/power_supply/BAT0
vendor: SANYO
model: UM08B32
power supply: yes
updated: Tue Nov 27 15:42:31 2012 (17 seconds ago)
has history: yes
has statistics: yes
battery
present: yes
rechargeable: yes
state: discharging
energy: 20.9196 Wh
energy-empty: 0 Wh
energy-full: 21.1248 Wh
energy-full-design: 48.6 Wh
energy-rate: 13.5432 W
voltage: 11.753 V
time to empty: 1.5 hours
percentage: 99.0286%
capacity: 43.4667%
technology: lithium-ion
History (charge):
1354023683 99.029 discharging
History (rate):
1354023751 13.543 discharging
2-3 minutes later:
native-path: /sys/devices/LNXSYSTM:00/device:00/PNP0A08:00/device:02/PNP0C0A:00/power_supply/BAT0
vendor: SANYO
model: UM08B32
power supply: yes
updated: Tue Nov 27 15:45:06 2012 (20 seconds ago)
has history: yes
has statistics: yes
battery
present: yes
rechargeable: yes
state: discharging
energy: 20.2824 Wh
energy-empty: 0 Wh
energy-full: 21.1248 Wh
energy-full-design: 48.6 Wh
energy-rate: 13.7484 W
voltage: 11.545 V
time to empty: 1.5 hours
percentage: 96.0123%
capacity: 43.4667%
technology: lithium-ion
History (charge):
1354023906 96.012 discharging
1354023844 97.035 discharging
History (rate):
1354023906 13.748 discharging
1354023875 12.992 discharging
1354023844 13.284 discharging
10 minutes later:
native-path: /sys/devices/LNXSYSTM:00/device:00/PNP0A08:00/device:02/PNP0C0A:00/power_supply/BAT0
vendor: SANYO
model: UM08B32
power supply: yes
updated: Tue Nov 27 15:54:24 2012 (28 seconds ago)
has history: yes
has statistics: yes
battery
present: yes
rechargeable: yes
state: discharging
energy: 18.1764 Wh
energy-empty: 0 Wh
energy-full: 21.1248 Wh
energy-full-design: 48.6 Wh
energy-rate: 13.2948 W
voltage: 11.268 V
time to empty: 1.4 hours
percentage: 86.0429%
capacity: 43.4667%
technology: lithium-ion
History (charge):
1354024433 86.043 discharging
History (rate):
1354024464 13.295 discharging
1354024433 13.662 discharging
1354024402 13.781 discharging
I noticed that between #2 and #3 (0 and 1 minutes after unplugging), while the battery still reports 99% charge and drops from 2:30 hr to 1:30 hr, the energy usage goes from 8.34 W to 13.54 W and the current_now increases, but shouldn't it be using less energy in battery mode since the screen is much dimmer and it's in power saving mode? (or is that normal behavior?)
It also seems to drain more quickly than what it predicts, especially with the 1-1.25 hour drop in the first minute of being unplugged, which seems odd.
What really concerns me is that Ubuntu 12.10 may not be properly managing the battery (with the sudden change in charge/life from 2:30 to 1:30 or 1:15 within a minute of unplugging), and that a new battery may quickly die under Ubuntu 12.10.
I'd greatly appreciate any advice/suggestions on what to do, and especially whether there's a way to get back the 1-1.5 hrs of battery life that were suddenly lost when changing from WinXp to Ubuntu 12.10.
Thanks :)
