new laptop battery problems

[Michal Brzozowski]

Hello,
I recently bought a new laptop and I noticed that
the battery won't charge up to the full capacity
(or as it says design capacity).

$ cat /proc/acpi/battery/BAT1/info

present: yes
design capacity: 4400 mAh
last full capacity: 3040 mAh
battery technology: rechargeable
design voltage: 14800 mV
design capacity warning: 300 mAh
design capacity low: 100 mAh
capacity granularity 1: 32 mAh
capacity granularity 2: 32 mAh
model number: 03ZG
serial number: 30030
battery type: LION
OEM info: SANYO

$ cat /proc/acpi/battery/BAT1/state

present: yes
capacity state: ok
charging state: charged
present rate: 0 mA
remaining capacity: 3040 mAh
present voltage: 16544 mV


First when I noticed this it stopped charging at 3400 mAh,
I've been trying different things like emptying/recharging
(about 8-10 times), removing/recharging, but as you see
it only became worse.

Will this fix by itself (I read that new batteries sometimes don't
charge to full capacity, but in this case the full capacity is
becoming lower and lower)?

 

[answers]

Well a new Lithium Ion battery require to be conditioned before use and
you have certainly tried it 8 - 10 times.

In my experience, I can safely say that the battery is faulty. It is
working but not delivering the full capacity. Since its new, you
should get a straight swap.

If the replacement behaves the same way, then there may be a setting on
the laptop that I have not come across before!! or a fault on the power
circuitry on the laptop.

Hope this helpful.

Battery Wizard
http://www.ComputerBatteries.co.uk

 

[Davy]

quote="Michal Brzozowsk

remaining capacity: 3040 mA
present voltage: 16544 m

Present voltage 16544mV or plainly 16.544V sounds a little odd whe
the designed voltage is 14.8V is this a battery fault or a charge
fault, think I would look at the charger first ..

Reason is I never hear of overcharging with the Nicad variet
although they 'are' different, a point that never been raised.....

Dav

 

[Michal Brzozowski]

Present voltage 16544mV or plainly 16.544V sounds a little odd when
the designed voltage is 14.8V is this a battery fault or a charger
fault, think I would look at the charger first ..?

Reason is I never hear of overcharging with the Nicad variety
although they 'are' different, a point that never been raised.....?

Davy

I noticed that too. When the battery is discharging, the voltage
becomes lower, even under 14,8 at the end. Maybe I should
take the whole laptop to the service?

 

[Davy]

Point is, you go out and buy a new battery if it happens to be th
charger then you are in the same predicament with a 'hole in th
pocket'

These chargers are so well regulated, no doubt also contain
overcurrent protection as well, what happens if the regulator ain'
regulating...

This is what I feared and why I posted, it may well be the battery bu
I doubt it, the tell tale is the 16.544 Volts and doubt that is
trait of Lithium Ion batteries, there are dedicated battery tester
for this very purpose but they are quite expensive, these thing
aren't testmeters as we know but can even tell you the discharge rat
in mA/hour

When a battery near's the end no matter what battery it's the interna
resistance that rises causes a voltage drop as current is draw
through this generated internal resistance, some types of batter
have varying 'knee characteristics', the ability to produce th
required voltage as it nears the end of its life, some are bette
than others at doing this

Mind you I could be wrong, good luck all the same

Dav

 

[kony]

Present voltage 16544mV or plainly 16.544V sounds a little odd when
the designed voltage is 14.8V is this a battery fault or a charger
fault, think I would look at the charger first ..?

Reason is I never hear of overcharging with the Nicad variety
although they 'are' different, a point that never been raised.....?

Davy

Typically a nominal voltage is 3.6 per cell but higher, as
much as 4.2 charged. Compare NiMH like this and you see a
supposed 1.2V cell is actually closer to 1.4V charged.

So with a 1.44/14.8 range pack that's 4 x Li-Ion cells in
it. 4 x 4.2 = 16.8V, it's pretty close to what we'd expect
to see, EXCEPT for that part about insufficient capacity.