On Tue, Nov 9, 2010 at 23:52, Paul Hartman <paul.hartman+gen...@gmail.com> wrote: > Hi, > > I have a laptop running Gentoo (with dual-boot to Windows XP). It was > manufactured in 2004 and battery life have been consistent for all > those years. However, it sat dormant for almost a year, after which I > did a few days worth of updating to bring it up to current kernel and > ~amd64 package levels. There are two issues that have arisen: > > 1) The smart battery is not so smart anymore. It only charges about > halfway, then the charging light turns green and it stops. Effective > battery capacity is about one-third of what it used to be. From what I > understand, while Li-ion don't have "memory" like old Ni-Cd batteries, > the "smart" circuitry cannot account for power drain that happens when > the battery is not in use. Say the battery lost half of its power > while it was in storage, so the chip thinks charge is at one level > when it is really much lower. When recharging, it stops when it is > "full" even though it's only halfway there. > > Has anyone successfully re-calibrated one of these batteries to > recognize a larger capacity? > > My understanding is that, to do this, I should discharge at a constant > rate until it is empty, then charge to full. Repeat ?? times. I've > drained the poor little battery after regular usage (not a constant > rate of discharge) a few times and haven't noticed any change so far. > So I'm probably doing it wrong (or completely misunderstanding...) >
AFAIK, this is the advised way to dis/charge Li-ion batteries to keep their performance up. But since you left it to sleep for a year, you probably lost some of the cells to death. You can perhaps try keep doing that not to loose any more of them. > This is complicated by my second problem: > > 2) If I click on the Power Management in the KDE system settings, it > says "Number of CPUs 0" "Number of batteries 0" and battery-related > options are greyed out. Since battery monitoring does not work, I have > no idea how much battery life is left and have no warning when it > suddenly shuts down, causing filesystem corruption and who knows what > other problems. > > Everything in /proc/acpi/battery/ seems normal and /proc/cpuinfo does as well: > > $ cat /proc/acpi/battery/BAT1/info > present: yes > design capacity: 4400 mAh > last full capacity: 1984 mAh [..] > $ cat /proc/acpi/battery/BAT1/state > present: yes > capacity state: ok > charging state: charged > present rate: 0 mA > remaining capacity: 1984 mAh > present voltage: 16384 mV Only ~45% [1985/4400*100] of your battery seems to be alive. For reference, I have 3062/4400*100 ~70% of a 5 year old battery here and I have not paid attention to the above mentioned dis/charge advise. I don't know why KDE cannot read. Try to check ~/.xsession-error for some useful error. FYI the remaining battery level is calculated by the following formula FYI: remaining capacity / last full capacity * 100 If youre planning to use this battery, either try other battery monitors or have a script to calculate above values periodically and give a warning. Otherwise at some point your system will get as corrupted as your battery. Good luck. -- Fatih
