[SOLVED] Brand new laptop, battery charges to 95% max (?)

kokoko3k · 2014-05-08 16:24:14

I've seen this widely on a simple google search for "last full capacity",
the laptop has been used for just two days, but acpi reports:

koko@TravelMate ~ $ acpi -biatc
Battery 0: Charging, 100%,  until charged
Battery 0: design capacity 4400 mAh, last full capacity 4182 mAh = 95%
Adapter 0: on-line
Cooling 0: x86_pkg_temp no state information available
Cooling 1: intel_powerclamp no state information available
Cooling 2: Processor 0 of 10
Cooling 3: Processor 0 of 10
Cooling 4: Processor 0 of 10
Cooling 5: Processor 0 of 10

it won't go higher than that.
Is that normal? maybe some sort of overcharge protection?
my previous netbook always charged to 100% or even a bit more than the design capacity...

Last edited by kokoko3k (2014-05-10 13:31:54)

chaonaut · 2014-05-08 17:09:33

kokoko3k wrote:

Is that normal? maybe some sort of overcharge protection?

may be. overcharge is not desirable for modern li-pol batteries, so many of modern hardware in fact does have some kind of overcharge protection.

Inxsible · 2014-05-08 18:14:25

Have you tried it in another OS like Windows? Does it do the same thing? Also check in the BIOS if it displays a charging level.

clfarron4 · 2014-05-08 18:31:23

chaonaut wrote:

kokoko3k wrote:
Is that normal? maybe some sort of overcharge protection?
may be. overcharge is not desirable for modern li-pol batteries, so many of modern hardware in fact does have some kind of overcharge protection.

Didn't DELL do this for a while with their laptops?

@kokoko3k: Have you run the battery to empty and fully charged it yet?

emeres · 2014-05-08 18:58:22

Depending on the technology used, one (or several) of the cells might be shorted or almost shorted. Another reason might be wrong measurement [circuit] from either battery or laptop side. And the simplest reason would be that the laptop/battery was produced some time ago, depending on type of technology used, certain batteries lose significant amount of capacity over time (even if unused). Since it is brand new, get in touch with your supplier and get at least the battery exchanged.
If you try to discharge it first, do fully discharge it using LEDs or some other low current load until voltage drops to approximately 10% of nominal voltage, and then recharge it not extending 110% of time it needed to be fully charged Repeating this cycle might and does help with certain types of batteries. If I were you, I would not bother however and go get a replacement from the shop, unless it is really troublesome.
As for overcharge protection, there are usually thermal (usually the most important one), shortcircuit and overcharge (meaning overvoltage protection) protections built into the battery (usually one ic) and/or laptop.

Last edited by emeres (2014-05-08 19:00:19)

ewaller · 2014-05-08 19:25:38

It can be near impossible to determine the charge state of Lithium Polymer or Lithium Ion batteries. They have an extremely shallow voltage vs charge curve. I have even seen the voltage be non-monotonic regions (it goes back up) as the batteries discharge. As such, devices that use these batteries count Coulombs in out out of the batteries by integrating the current vs time. Sometimes these circuits lose track of some of the charge. Usually, this happens if the device has not been powered on for an extended period and the batteries experience some self discharge (which, by nature, don't pass through the counter) When the battery is subsequently charged, the battery reaches a full state and charging stops prior to the Coulomb counter reaching full scale. This condition is impossible to differentiate from a battery that no longer charges to its design capacity (wear out) given the information available. This is why it is sometimes necessary to 'Calibrate' a battery. The battery should be allowed to run down to the point where the system shuts down. Modern battery monitors will use this point on the discharge curve as the new datum for the charge state and, after the next charge cycle, should have an accurate value for the fully charged state. If it is still low, the battery has a diminished capacity. Note that some older battery supervisors did not automatically reset the datum at the end of the discharge cycle. Those systems generally have a BIOS option for calibrating the battery. Those tools keep setting the low water mark as the battery discharges until such time as it dies. Overall, it is the same effect.

ewaller · 2014-05-08 19:42:18

emeres wrote:

Depending on the technology used, one (or several) of the cells might be shorted or almost shorted. Another reason might be wrong measurement [circuit] from either battery or laptop side. And the simplest reason would be that the laptop/battery was produced some time ago, depending on type of technology used, certain batteries lose significant amount of capacity over time (even if unused). Since it is brand new, get in touch with your supplier and get at least the battery exchanged.
If you try to discharge it first, do fully discharge it using LEDs or some other low current load until voltage drops to approximately 10% of nominal voltage, and then recharge it not extending 110% of time it needed to be fully charged Repeating this cycle might and does help with certain types of batteries. If I were you, I would not bother however and go get a replacement from the shop, unless it is really troublesome.
As for overcharge protection, there are usually thermal (usually the most important one), shortcircuit and overcharge (meaning overvoltage protection) protections built into the battery (usually one ic) and/or laptop.

None of that is applicable for Lithium Polymer or Lithium Ion batteries. They should never drop below 3 volts. Discharging them below that point will destroy them and risk a fire. Charging Lithium based batteries is also non trivial and requires tight monitoring of voltage and controls on current and time. Do not mess with LiPoly or LiIon, they truly represent a serious safety hazard if they are mistreated. I note that your suggestions and descriptions of shorted cells are applicable to some non Li technologies; notably Nickle based batteries (Nickle Cadmium, Nickle Metal Hydride, etc...) In general, those are not found in modern laptops because of their toxicity and relatively low energy density as compared to LiPoly.

http://www.empirerc.com/liposafety.htm
http://www.rcpro.org/net/ThreadView.aspx?threadid=260
http://magazine.sfpe.org/content/lithiu … ry-hazards
http://www.datasheetdir.com/BQ29400+download
http://batteryuniversity.com/learn/arti … _batteries
http://www.batteryuniversity.com/learn/ … ith_li_ion

Last edited by ewaller (2014-05-09 03:00:19)

emeres · 2014-05-08 19:46:25

ewaller wrote:

emeres wrote:
Depending on the technology used, one (or several) of the cells might be shorted or almost shorted. Another reason might be wrong measurement [circuit] from either battery or laptop side. And the simplest reason would be that the laptop/battery was produced some time ago, depending on type of technology used, certain batteries lose significant amount of capacity over time (even if unused). Since it is brand new, get in touch with your supplier and get at least the battery exchanged.
If you try to discharge it first, do fully discharge it using LEDs or some other low current load until voltage drops to approximately 10% of nominal voltage, and then recharge it not extending 110% of time it needed to be fully charged Repeating this cycle might and does help with certain types of batteries. If I were you, I would not bother however and go get a replacement from the shop, unless it is really troublesome.
As for overcharge protection, there are usually thermal (usually the most important one), shortcircuit and overcharge (meaning overvoltage protection) protections built into the battery (usually one ic) and/or laptop.
None of that is applicable for Lithium Polymer or Lithium Ion batteries. They should never drop below 3 volts. Discharging them below that point will destroy them and risk a fire. Charging Lithium based batteries is also non trivial and requires tight monitoring of voltage and controls on current and time. Do not mess with LiPoly or LiIon, they truly represent a serious safety hazard if they are mistreated. I note that your suggestions and descriptions of shorted cells are applicable to some non Li technologies; notably Nickle based batteries (Nickle Cadmium, Nickle Metal Hydride, etc...) In general, those are not found in modern laptops because of their toxicity and relatively low energy density as compared to LiPoly.

emeres wrote:

Depending on the technology used

ewaller · 2014-05-08 19:52:00

Noted. But applying what you wrote to the wrong battery chemistry would lead to disaster. This includes the destruction of the battery, fire, and injury through contact with caustic substances. I really don't want our readers to try screwing with LiPoly or LiIon. Seriously, do not try this at home.

emeres · 2014-05-08 23:15:44

Dear ewaller, I usually do not argue, because it is often non-productive and of no interest to OP. I will make an exception in this case however.

ewaller wrote:

But applying what you wrote to the wrong battery chemistry would lead to disaster. This includes the destruction of the battery, fire, and injury through contact with caustic substances.

Not really, no. I did not state to short leads or use a high current load, but suggested using LEDs (usually > 3 kOhm, no reference to high current LEDs, obviously in series topology at higher voltages, dropping down to one in the end) or other high resistance load. Even in optimal conditions one would get 1,5 mW from the whole circuit with the 3 V voltage you referred to, so 750 microW in the battery [cell] itself. This is of no concern. I did this several times, it is safe. There may be exceptions (military hardware, undisclosed technology), but very unlikely to be found on the civil market. Again, I did not state to force a precisely specified voltage (stated only an approximation, which can be very loose), short leads or use a low resistance sink. The only downside is... it takes a very long time, even on small capacity Li-ion phone batteries. The voltage would not drop below the safe level in Li-ion or Li-poly batteries for a very long time. And if it did, nothing would happen with that load (> 3 kOhm). Dropping to bellow should be avoided, but does not poses a threat if done correctly. I think you interpreted that I suggested fast discharging using a very low resistance load, which I did not. Loading should be done with appropriate hardware.
Yes, it can be dangerous, when done improperly. There is no question about it, I assume however that people use their head, otherwise it is only a question of time till something bad happens. I do not wish any harm or destruction either dear ewaller.

ewaller · 2014-05-09 02:46:18

kokoko3k,
Sorry for having contributed to reducing the signal to noise ratio of your thread. I had no choice but to address some dangerously bad advice.

Putting an end to that, are you going to have a chance to run those batteries all the way down? Before you do, you probably should poke around your BIOS and see if there are any calibration tools in there. Also, I assume your box came with an operating system preinstalled. If you still have access to that OS, check to see if it has any battery calibration tools.

kokoko3k · 2014-05-09 10:56:30

My question was just a curiosity.

@ewaller:
No need to worry about noise at all, i found the post of both of you really informative (even if i've still to understand them completely); unfortunately, when speak about batteries, there are also a lot of advices contraddicting themselves.
But the common thing seems to try to calibrate the battery, and i'm going to to it.

@emeres:
Trying to return the battery is not an option, i've got the laptop online, it is difficult to return it and have it back; in the end we're talking just 5% which translate to about 10minutes of real laptop use.

kokoko3k · 2014-05-09 11:41:50

Sorry for the wild quoting, but this is important for me to understand properly.

ewaller wrote:

The battery should be allowed to run down to the point where the system shuts down.

Is the "system" the operating system? or should i let the laptop shut down as late as it can... by his own?
You mean the latter, right?

ewaller wrote:

Modern battery monitors will use this point on the discharge curve as the new datum for the charge state

What i understood is that they update the "datum" anytime they find a lower point of discharge (?)

Have i got it right?

emeres · 2014-05-09 14:11:54

kokoko3k wrote:

@emeres:
Trying to return the battery is not an option, i've got the laptop online, it is difficult to return it and have it back; in the end we're talking just 5% which translate to about 10minutes of real laptop use.

That is unfortunate. Could you name that particular online shop? I would not wish to be in the same situation, if I could avoid it.

kokoko3k · 2014-05-09 14:26:39

It is not the shop itself, it is the Italy

ewaller · 2014-05-09 14:40:26

kokoko3k wrote:

Is the "system" the operating system? or should i let the laptop shut down as late as it can... by his own?
You mean the latter, right?

Correct. Run it until the hardware shuts itself off.

What i understood is that they update the "datum" anytime they find a lower point of discharge (?)
Have i got it right?

You got it

kokoko3k · 2014-05-09 19:11:22

Ok, i'll leave it in standby overnight, 10x!

kokoko3k · 2014-05-10 11:26:45

I left the laptop to discharge very slowly over night till it powered off.
As soon as i plugged the AC again, the upper limit raised from 95% to 98%.
Thanks.

I'm sorry for the little OT, but what are the best pratices to keep the battery as healtly as possible over time if any?
Somebody tells to charge it a little every time you stop to use it, somebody else think that you should never let it go down to anything under 50%.
Seems that everybody has his own idea

emeres · 2014-05-10 12:51:00

kokoko3k wrote:

I'm sorry for the little OT, but what are the best pratices to keep the battery as healtly as possible over time if any?
Somebody tells to charge it a little every time you stop to use it, somebody else think that you should never let it go down to anything under 50%.
Seems that everybody has his own idea

Either contact the manufacturer or get a hold of technical notes/scientific papers for/about your battery [cells]. They design it, they know best.

clfarron4 · 2014-05-10 13:39:51

kokoko3k wrote:

I left the laptop to discharge very slowly over night till it powered off.
As soon as i plugged the AC again, the upper limit raised from 95% to 98%.
Thanks.
I'm sorry for the little OT, but what are the best pratices to keep the battery as healtly as possible over time if any?
Somebody tells to charge it a little every time you stop to use it, somebody else think that you should never let it go down to anything under 50%.
Seems that everybody has his own idea

The advice is different depending on who you ask. You should definitely drain it to empty once a month and then charge it fully, that way you know just how long it actually lasts.

kokoko3k · 2014-05-10 16:42:23

thanks clfarron4, i'll certanly do that from time to time.

Arch Linux

#1 2014-05-08 16:24:14

[SOLVED] Brand new laptop, battery charges to 95% max (?)

#2 2014-05-08 17:09:33

Re: [SOLVED] Brand new laptop, battery charges to 95% max (?)

#3 2014-05-08 18:14:25

Re: [SOLVED] Brand new laptop, battery charges to 95% max (?)

#4 2014-05-08 18:31:23

Re: [SOLVED] Brand new laptop, battery charges to 95% max (?)

#5 2014-05-08 18:58:22

Re: [SOLVED] Brand new laptop, battery charges to 95% max (?)

#6 2014-05-08 19:25:38

Re: [SOLVED] Brand new laptop, battery charges to 95% max (?)

#7 2014-05-08 19:42:18

Re: [SOLVED] Brand new laptop, battery charges to 95% max (?)

#8 2014-05-08 19:46:25

Re: [SOLVED] Brand new laptop, battery charges to 95% max (?)

#9 2014-05-08 19:52:00

Re: [SOLVED] Brand new laptop, battery charges to 95% max (?)

#10 2014-05-08 23:15:44

Re: [SOLVED] Brand new laptop, battery charges to 95% max (?)

#11 2014-05-09 02:46:18

Re: [SOLVED] Brand new laptop, battery charges to 95% max (?)

#12 2014-05-09 10:56:30

Re: [SOLVED] Brand new laptop, battery charges to 95% max (?)

#13 2014-05-09 11:41:50

Re: [SOLVED] Brand new laptop, battery charges to 95% max (?)

#14 2014-05-09 14:11:54

Re: [SOLVED] Brand new laptop, battery charges to 95% max (?)

#15 2014-05-09 14:26:39

Re: [SOLVED] Brand new laptop, battery charges to 95% max (?)

#16 2014-05-09 14:40:26

Re: [SOLVED] Brand new laptop, battery charges to 95% max (?)

#17 2014-05-09 19:11:22

Re: [SOLVED] Brand new laptop, battery charges to 95% max (?)

#18 2014-05-10 11:26:45

Re: [SOLVED] Brand new laptop, battery charges to 95% max (?)

#19 2014-05-10 12:51:00

Re: [SOLVED] Brand new laptop, battery charges to 95% max (?)

#20 2014-05-10 13:39:51

Re: [SOLVED] Brand new laptop, battery charges to 95% max (?)

#21 2014-05-10 16:42:23

Re: [SOLVED] Brand new laptop, battery charges to 95% max (?)

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