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battery issue?



 
 
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  #1  
Old October 16th 14, 09:03 PM posted to microsoft.public.windowsxp.hardware
Jo-Anne[_4_]
external usenet poster
 
Posts: 1,098
Default battery issue?

Using WinXP on a 6-year-old Dell Precision 4300 laptop. I had the
battery replaced a few days ago when it wasn't charging properly.
Everything was fine until I took the laptop back yesterday to have it
blown out and the fan checked (first time ever). Since then, the taskbar
icon that shows the battery being charged is constantly on instead of
reverting to "AC Power" when it's finished charging. At first it was on
even when the battery was charged 100%. I unplugged the machine long
enough to let the battery discharge a bit and then plugged it back in.
Now it's claiming to be charging all the time at 99% charged.

Any idea what could be causing the problem? And, even more important, is
it dangerous? I called the repair place, and the technician I talked to
said that probably a signal was being misread and it wasn't a problem.

Thank you,

Jo-Anne
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  #2  
Old October 16th 14, 10:37 PM posted to microsoft.public.windowsxp.hardware
Paul
external usenet poster
 
Posts: 18,281
Default battery issue?

Jo-Anne wrote:
Using WinXP on a 6-year-old Dell Precision 4300 laptop. I had the
battery replaced a few days ago when it wasn't charging properly.
Everything was fine until I took the laptop back yesterday to have it
blown out and the fan checked (first time ever). Since then, the taskbar
icon that shows the battery being charged is constantly on instead of
reverting to "AC Power" when it's finished charging. At first it was on
even when the battery was charged 100%. I unplugged the machine long
enough to let the battery discharge a bit and then plugged it back in.
Now it's claiming to be charging all the time at 99% charged.

Any idea what could be causing the problem? And, even more important, is
it dangerous? I called the repair place, and the technician I talked to
said that probably a signal was being misread and it wasn't a problem.

Thank you,

Jo-Anne


This is purely an *opinion* on my part - there is
no such thing as "not a problem" with lithium batteries.

The battery itself has additional internal protection,
to cover against cases of overcharging. But we don't
go around wishing for that to be triggered. There is a link
inside each cell, which opens and ruins the battery,
if you abuse the battery. The abuse could be caused by,
say, a defective charging chip inside the laptop, not
some habit of the user. The user is blameless in this.
In fact, your observation that it hit 99% and isn't stopping,
is more than most users would even realize.

The charger circuit is considered a "precision" device,
because of the dangers associated with lithium. It's not
a crappy charger, like your Black and Decker screwdriver
used to use for the NiCD batteries it came with. Laptops are
generally very careful not to overcharge the battery. But
circuits die, and so the batteries themselves have additional
(physical) protection.

*******

The article on charging is here.

http://batteryuniversity.com/learn/a..._ion_batteries

The diagram is here. Let's compare your symptoms.

http://batteryuniversity.com/_img/content/ion1.jpg

In Stage 1, if the battery was really run down, and the
battery terminal voltage was a lot lower than the "stiff"
power supply of the wall adapter, a lot of current would flow.

What the charging circuit does instead, is run in "constant current
mode". This limits the Stage 1 current run through the battery.
The Stage 1 portion of the charge cycle, provides the majority
of the energy in the battery. The battery becomes mostly
charged in Stage 1.

Stage 2 is for "tapering the charge". We wish to "top up" the
battery, without hurting it. This is done at a constant voltage.
So when the Stage 1 charging process reaches the correct terminal
voltage, the power source switches to constant voltage mode. The
voltage difference between the power source and the battery, is
tiny, and Vdiff/Rbatt gives the current. As the battery fills up,
the Vdiff difference drops and drops. The current that flows into
the battery, asymptotically approaches zero.

The charger sets an arbitrary limit, and when the current drops
to just 3% of the constant current value, the charger considers
the tapering process to be "full". The charger stops work on
the battery at that point.

In stage 3, the electrolyte composition stabilizes, in the sense
that any ionic concentration near the plates, can spread through
the electrolyte. The terminal voltage drops a bit, since the
battery is no longer charging, and it can "relax". (If you are
charging your car battery, this is why you wait until the next
day, to check the terminal voltage. If you want to measure
the "true value". Don't check the battery voltage just after
you take the charger cables off it. Doing a lead acid electrolyte
density measurement, might not be quite as sensitive to the passage
of time. Car batteries are really tricky, as the results are
quite temperature sensitive, and it's hard to tell the difference
between a half-full battery and a full one. Temperature makes
that much of a difference to the physics.)

So right now, you're in Stage 2, but the current is not tapering
off. Instead of being at 3% current flow, you're at 5% or 10%.
The battery should not be left in this state. While NiCDs can
tolerate C/10 or C/20 trickle forever, we're not supposed to do
that to lithium.

My question would be, why is the battery not able to charge
to the terminal voltage that the charger is attempting to
place on it ? It sounds like the cells in the battery, aren't
a match for the charger circuit. Like, a generic battery was
purchased, the cell chemistry is subtly different, and the
charge cycle is not able to complete.

The above is all my own opinion, based on that one page
from the batteryuniversity site. Perhaps someone else
will have another interpretation.

*******

Possible responses to this problem:

1) Perform a calibration cycle.

Disconnect AC. Run the laptop until the battery is drained.
The laptop should shut itself off. Observe the behavior near
the end of charge carefully. If the battery is not matched at
the top end, it's not likely to behave well at the bottom end
either. For example, the battery might "drain", before the laptop
hibernates on its own. This again implies the charge management
doesn't know the correct knee voltage, the machine hits the knee,
and the battery flattens before hibernate can trigger. A dirty
shutdown results, and since NTFS is journaled, there's hardly
ever a ptoblem.

Now, with the battery drained, run a charge cycle. Watch the
process carefully. Does it hit 100% and stop charging ? Or is
it still stuck at 99%.

The purpose of a complete discharge, is in case the machine uses
some sort of coulomb measure of capacity. There is supposed to be
some recalibration procedure, which should happen when a full discharge
is applied.

Check the manual to see if there is any mention of recalibration.
Some batteries have a serial bus connection, and a smart chip inside
the battery, gives "fuel readings" to the laptop. A second reason
for having a smart chip, is to prevent third parties from
making a "fully compatible" product. Just like printer cartridges
or inkjets are "chipped".

2) If you don't want to waste another dime on batteries, then
charge to 99%, and immediately unplug the adapter when you
hit 99%. If there is a (theoretical) problem with trickle
charging it forever, unplugging the adapter will stop the behavior.
In effect, you the user, are cutting off the end of Stage 2, by
pulling the plug.

3) If you don't like the inconvenience of (2), you've tried (1)
or whatever passes in the user manual for battery calibration,
seek to purchase another (legit) battery.

HTH,
Paul
  #3  
Old October 17th 14, 04:49 AM posted to microsoft.public.windowsxp.hardware
Jo-Anne[_4_]
external usenet poster
 
Posts: 1,098
Default battery issue?

On 10/16/2014 4:37 PM, Paul wrote:
Jo-Anne wrote:
Using WinXP on a 6-year-old Dell Precision 4300 laptop. I had the
battery replaced a few days ago when it wasn't charging properly.
Everything was fine until I took the laptop back yesterday to have it
blown out and the fan checked (first time ever). Since then, the
taskbar icon that shows the battery being charged is constantly on
instead of reverting to "AC Power" when it's finished charging. At
first it was on even when the battery was charged 100%. I unplugged
the machine long enough to let the battery discharge a bit and then
plugged it back in. Now it's claiming to be charging all the time at
99% charged.

Any idea what could be causing the problem? And, even more important,
is it dangerous? I called the repair place, and the technician I
talked to said that probably a signal was being misread and it wasn't
a problem.

Thank you,

Jo-Anne


This is purely an *opinion* on my part - there is
no such thing as "not a problem" with lithium batteries.

The battery itself has additional internal protection,
to cover against cases of overcharging. But we don't
go around wishing for that to be triggered. There is a link
inside each cell, which opens and ruins the battery,
if you abuse the battery. The abuse could be caused by,
say, a defective charging chip inside the laptop, not
some habit of the user. The user is blameless in this.
In fact, your observation that it hit 99% and isn't stopping,
is more than most users would even realize.

The charger circuit is considered a "precision" device,
because of the dangers associated with lithium. It's not
a crappy charger, like your Black and Decker screwdriver
used to use for the NiCD batteries it came with. Laptops are
generally very careful not to overcharge the battery. But
circuits die, and so the batteries themselves have additional
(physical) protection.

*******

The article on charging is here.

http://batteryuniversity.com/learn/a..._ion_batteries

The diagram is here. Let's compare your symptoms.

http://batteryuniversity.com/_img/content/ion1.jpg

In Stage 1, if the battery was really run down, and the
battery terminal voltage was a lot lower than the "stiff"
power supply of the wall adapter, a lot of current would flow.

What the charging circuit does instead, is run in "constant current
mode". This limits the Stage 1 current run through the battery.
The Stage 1 portion of the charge cycle, provides the majority
of the energy in the battery. The battery becomes mostly
charged in Stage 1.

Stage 2 is for "tapering the charge". We wish to "top up" the
battery, without hurting it. This is done at a constant voltage.
So when the Stage 1 charging process reaches the correct terminal
voltage, the power source switches to constant voltage mode. The
voltage difference between the power source and the battery, is
tiny, and Vdiff/Rbatt gives the current. As the battery fills up,
the Vdiff difference drops and drops. The current that flows into
the battery, asymptotically approaches zero.

The charger sets an arbitrary limit, and when the current drops
to just 3% of the constant current value, the charger considers
the tapering process to be "full". The charger stops work on
the battery at that point.

In stage 3, the electrolyte composition stabilizes, in the sense
that any ionic concentration near the plates, can spread through
the electrolyte. The terminal voltage drops a bit, since the
battery is no longer charging, and it can "relax". (If you are
charging your car battery, this is why you wait until the next
day, to check the terminal voltage. If you want to measure
the "true value". Don't check the battery voltage just after
you take the charger cables off it. Doing a lead acid electrolyte
density measurement, might not be quite as sensitive to the passage
of time. Car batteries are really tricky, as the results are
quite temperature sensitive, and it's hard to tell the difference
between a half-full battery and a full one. Temperature makes
that much of a difference to the physics.)

So right now, you're in Stage 2, but the current is not tapering
off. Instead of being at 3% current flow, you're at 5% or 10%.
The battery should not be left in this state. While NiCDs can
tolerate C/10 or C/20 trickle forever, we're not supposed to do
that to lithium.

My question would be, why is the battery not able to charge
to the terminal voltage that the charger is attempting to
place on it ? It sounds like the cells in the battery, aren't
a match for the charger circuit. Like, a generic battery was
purchased, the cell chemistry is subtly different, and the
charge cycle is not able to complete.

The above is all my own opinion, based on that one page
from the batteryuniversity site. Perhaps someone else
will have another interpretation.

*******

Possible responses to this problem:

1) Perform a calibration cycle.

Disconnect AC. Run the laptop until the battery is drained.
The laptop should shut itself off. Observe the behavior near
the end of charge carefully. If the battery is not matched at
the top end, it's not likely to behave well at the bottom end
either. For example, the battery might "drain", before the laptop
hibernates on its own. This again implies the charge management
doesn't know the correct knee voltage, the machine hits the knee,
and the battery flattens before hibernate can trigger. A dirty
shutdown results, and since NTFS is journaled, there's hardly
ever a ptoblem.

Now, with the battery drained, run a charge cycle. Watch the
process carefully. Does it hit 100% and stop charging ? Or is
it still stuck at 99%.

The purpose of a complete discharge, is in case the machine uses
some sort of coulomb measure of capacity. There is supposed to be
some recalibration procedure, which should happen when a full discharge
is applied.

Check the manual to see if there is any mention of recalibration.
Some batteries have a serial bus connection, and a smart chip inside
the battery, gives "fuel readings" to the laptop. A second reason
for having a smart chip, is to prevent third parties from
making a "fully compatible" product. Just like printer cartridges
or inkjets are "chipped".

2) If you don't want to waste another dime on batteries, then
charge to 99%, and immediately unplug the adapter when you
hit 99%. If there is a (theoretical) problem with trickle
charging it forever, unplugging the adapter will stop the behavior.
In effect, you the user, are cutting off the end of Stage 2, by
pulling the plug.

3) If you don't like the inconvenience of (2), you've tried (1)
or whatever passes in the user manual for battery calibration,
seek to purchase another (legit) battery.

HTH,
Paul



Thank you, Paul! Right now, I'm trying to let the battery run down
completely. Then I'll charge it and see what happens. I'm beginning to
suspect that it was when the repair place stress tested the computer
after cleaning it (I had complained that it was running hot) that the
battery problem occurred--which may mean the new battery is bad.

Jo-Anne
  #4  
Old October 17th 14, 03:54 PM posted to microsoft.public.windowsxp.hardware
Jo-Anne[_4_]
external usenet poster
 
Posts: 1,098
Default battery issue?

On 10/16/2014 4:37 PM, Paul wrote:
Jo-Anne wrote:
Using WinXP on a 6-year-old Dell Precision 4300 laptop. I had the
battery replaced a few days ago when it wasn't charging properly.
Everything was fine until I took the laptop back yesterday to have it
blown out and the fan checked (first time ever). Since then, the
taskbar icon that shows the battery being charged is constantly on
instead of reverting to "AC Power" when it's finished charging. At
first it was on even when the battery was charged 100%. I unplugged
the machine long enough to let the battery discharge a bit and then
plugged it back in. Now it's claiming to be charging all the time at
99% charged.

Any idea what could be causing the problem? And, even more important,
is it dangerous? I called the repair place, and the technician I
talked to said that probably a signal was being misread and it wasn't
a problem.

Thank you,

Jo-Anne


This is purely an *opinion* on my part - there is
no such thing as "not a problem" with lithium batteries.

The battery itself has additional internal protection,
to cover against cases of overcharging. But we don't
go around wishing for that to be triggered. There is a link
inside each cell, which opens and ruins the battery,
if you abuse the battery. The abuse could be caused by,
say, a defective charging chip inside the laptop, not
some habit of the user. The user is blameless in this.
In fact, your observation that it hit 99% and isn't stopping,
is more than most users would even realize.

The charger circuit is considered a "precision" device,
because of the dangers associated with lithium. It's not
a crappy charger, like your Black and Decker screwdriver
used to use for the NiCD batteries it came with. Laptops are
generally very careful not to overcharge the battery. But
circuits die, and so the batteries themselves have additional
(physical) protection.

*******

The article on charging is here.

http://batteryuniversity.com/learn/a..._ion_batteries

The diagram is here. Let's compare your symptoms.

http://batteryuniversity.com/_img/content/ion1.jpg

In Stage 1, if the battery was really run down, and the
battery terminal voltage was a lot lower than the "stiff"
power supply of the wall adapter, a lot of current would flow.

What the charging circuit does instead, is run in "constant current
mode". This limits the Stage 1 current run through the battery.
The Stage 1 portion of the charge cycle, provides the majority
of the energy in the battery. The battery becomes mostly
charged in Stage 1.

Stage 2 is for "tapering the charge". We wish to "top up" the
battery, without hurting it. This is done at a constant voltage.
So when the Stage 1 charging process reaches the correct terminal
voltage, the power source switches to constant voltage mode. The
voltage difference between the power source and the battery, is
tiny, and Vdiff/Rbatt gives the current. As the battery fills up,
the Vdiff difference drops and drops. The current that flows into
the battery, asymptotically approaches zero.

The charger sets an arbitrary limit, and when the current drops
to just 3% of the constant current value, the charger considers
the tapering process to be "full". The charger stops work on
the battery at that point.

In stage 3, the electrolyte composition stabilizes, in the sense
that any ionic concentration near the plates, can spread through
the electrolyte. The terminal voltage drops a bit, since the
battery is no longer charging, and it can "relax". (If you are
charging your car battery, this is why you wait until the next
day, to check the terminal voltage. If you want to measure
the "true value". Don't check the battery voltage just after
you take the charger cables off it. Doing a lead acid electrolyte
density measurement, might not be quite as sensitive to the passage
of time. Car batteries are really tricky, as the results are
quite temperature sensitive, and it's hard to tell the difference
between a half-full battery and a full one. Temperature makes
that much of a difference to the physics.)

So right now, you're in Stage 2, but the current is not tapering
off. Instead of being at 3% current flow, you're at 5% or 10%.
The battery should not be left in this state. While NiCDs can
tolerate C/10 or C/20 trickle forever, we're not supposed to do
that to lithium.

My question would be, why is the battery not able to charge
to the terminal voltage that the charger is attempting to
place on it ? It sounds like the cells in the battery, aren't
a match for the charger circuit. Like, a generic battery was
purchased, the cell chemistry is subtly different, and the
charge cycle is not able to complete.

The above is all my own opinion, based on that one page
from the batteryuniversity site. Perhaps someone else
will have another interpretation.

*******

Possible responses to this problem:

1) Perform a calibration cycle.

Disconnect AC. Run the laptop until the battery is drained.
The laptop should shut itself off. Observe the behavior near
the end of charge carefully. If the battery is not matched at
the top end, it's not likely to behave well at the bottom end
either. For example, the battery might "drain", before the laptop
hibernates on its own. This again implies the charge management
doesn't know the correct knee voltage, the machine hits the knee,
and the battery flattens before hibernate can trigger. A dirty
shutdown results, and since NTFS is journaled, there's hardly
ever a ptoblem.

Now, with the battery drained, run a charge cycle. Watch the
process carefully. Does it hit 100% and stop charging ? Or is
it still stuck at 99%.

The purpose of a complete discharge, is in case the machine uses
some sort of coulomb measure of capacity. There is supposed to be
some recalibration procedure, which should happen when a full discharge
is applied.

Check the manual to see if there is any mention of recalibration.
Some batteries have a serial bus connection, and a smart chip inside
the battery, gives "fuel readings" to the laptop. A second reason
for having a smart chip, is to prevent third parties from
making a "fully compatible" product. Just like printer cartridges
or inkjets are "chipped".

2) If you don't want to waste another dime on batteries, then
charge to 99%, and immediately unplug the adapter when you
hit 99%. If there is a (theoretical) problem with trickle
charging it forever, unplugging the adapter will stop the behavior.
In effect, you the user, are cutting off the end of Stage 2, by
pulling the plug.

3) If you don't like the inconvenience of (2), you've tried (1)
or whatever passes in the user manual for battery calibration,
seek to purchase another (legit) battery.

HTH,
Paul



UPDATE: I let the battery run completely down last night and then
recharged it--and it's showing now that it's fully charged and not
continuing to charge. I have no idea why this has happened or if it will
continue to look "normal."

Jo-Anne
 




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