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Re: The battery cannot be identified.

Just put in the new battery and it started up right away with no AC power needed.  I guess it was faulty hardware.

Thank you all so much (especially you Bob),

On Thu, Apr 7, 2011 at 11:29 AM, Peter Rapisarda <peter.rapisarda@gmail.com> wrote:
One more thing.  I checked in my /sys directory again for the power_supply just to see what happens.  When I checked the first time I must not have had the battery inserted because now I have AC and BAT0 in power_supply directory.

I ran ls -last on the BAT0 directory in the sys directory and this is what came up:

total 0
-rw-r--r-- 1 root root 4096 2011-03-10 06:06 alarm
drwxr-xr-x 2 root root    0 2011-03-10 06:04 power
-r--r--r-- 1 root root 4096 2011-03-10 05:23 charge_full
-r--r--r-- 1 root root 4096 2011-03-10 05:23 charge_now
-r--r--r-- 1 root root 4096 2011-03-10 05:23 current_now
-r--r--r-- 1 root root 4096 2011-03-10 05:23 status
-r--r--r-- 1 root root 4096 2011-03-10 05:23 charge_full_design
-r--r--r-- 1 root root 4096 2011-03-10 05:23 manufacturer
-r--r--r-- 1 root root 4096 2011-03-10 05:23 model_name
-r--r--r-- 1 root root 4096 2011-03-10 05:23 present
-r--r--r-- 1 root root 4096 2011-03-10 05:23 serial_number
-r--r--r-- 1 root root 4096 2011-03-10 05:23 voltage_min_design
-r--r--r-- 1 root root 4096 2011-03-10 05:23 voltage_now
lrwxrwxrwx 1 root root    0 2011-03-10 05:23 device -> ../../../devices/LNXSYSTM:00/device:00/PNP0C0A:00
lrwxrwxrwx 1 root root    0 2011-03-10 05:23 subsystem -> ../../power_supply
-r--r--r-- 1 root root 4096 2011-03-10 05:23 technology
-rw-r--r-- 1 root root 4096 2011-03-10 05:23 uevent
-r--r--r-- 1 root root 4096 2011-03-10 05:23 type
drwxr-xr-x 3 root root    0 2011-03-10 05:22 .
drwxr-xr-x 4 root root    0 2011-03-10 05:22 ..

I don't know if any of this is helpful but I just thought I'd share.  Just to be sure I made certain the battery was inserted and removed the AC power and it still shuts off.

On Wed, Apr 6, 2011 at 3:43 PM, Bob Proulx <bob@proulx.com> wrote:
Peter Rapisarda wrote:
> cat /proc/acpi/battery/BAT0/info
> present:                 yes

This information is in conflict with the previous information that you
posted saying that you didn't have any battery directories but just AC
directories.  Perhaps between then and now your battery became
connected?  Because at boot time if the battery is detected then it
should provide this directory of information.  If it isn't then it
doesn't.  It is fully dynamic with every boot.  The /proc isn't really
a filesystem but an interface to the kernel.  It is a memory only
filesystem presenting an interface of information and controls.

> design capacity:         4400 mAh

The battery says it has a vendor new rating of 4.4 amp-hours.  (It can
supply one amp of current for 4.4 hours.  Or two amps of current for
2.2 hours.  A typical machine pulls between 1-2 amps during running
and that would normally provide between 2-4 hours of runtime.)

> last full capacity:      3334 mAh

The battery says that when last charged it was able to hold 3.3 amp
hours of charge.  That is a degradation of 75% from new.  That isn't
terribly terrible.  My own main battery is sitting at around 90% at
the moment.  (I have a big extended capacity 9 cell 7.7 AH battery.
The standard 6-cell for my machine has around 4.6 AH standard
capacity.)  Batteries age over time as they are used.  If it were
really very bad then I would expect it to say something down in the
one amp-hour range.

The rest of the information is vaguely interesting data about the
battery and was pretty much as expected.  But there was something that
seemed a little odd to me.

> battery technology:      rechargeable
> design voltage:          14800 mV
> design capacity warning: 440 mAh
> design capacity low:     133 mAh
> capacity granularity 1:  44 mAh
> capacity granularity 2:  44 mAh
> model number:            DELL53LSN
> serial number:           678
> battery type:            LION
> OEM info:                Sanyo
> cat /proc/acpi/battery/BAT0/state
> present:                 yes
> capacity state:          ok
> charging state:          charged
> present rate:            1 mA
> remaining capacity:      4400 mAh
> present voltage:         16748 mV

Here it is showing that while the battery is charged that it is still
charging the battery at a rate of 1 milli-amp.  If it is charged then
I would expect the rate to be zero.  Otherwise it will continue to
charge (although at a very slow rate) which will eventually "cook" the
battery.  Excess charge can't be stored after the battery is fully
chemically converted and the excess energy will be converted to heat
energy.  This is a topic that everyone has an opinion upon and my
opinion is that this often results in out-gassing of battery chemicals
resulting in reduced battery capacity.

> Does this mean anything to you?  And just to be clear this is the old,
> presumably non-functioning, battery.

That data doesn't look like a non-functioning battery.  It looks like
it has 3.3 AH of capacity.  If you removed the AC power it should
provide power to your laptop for at least some while.  If you could
see the rate that it was discharging at that time then you would be
able to calculate an approximate runtime for that battery.  However I
have found that in practice the firmware calculating these values may
be wildly optimistic and the values may change wildly during
operation.  In other words...  You have to try it and see how well it
actually performs and even though it says 3.3 AH it may result in
something much different after a few battery cycles.

But if you remove AC power and the machine drops out immediately
without any sign of battery being used then something bad is
happening.  Perhaps the firmware is lying to you.  It wouldn't be the
first time.  Or something else must be wrong.  At that point I don't


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