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can you fix battery polarity-reveral?

Last response: in Laptops & Notebooks
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July 1, 2004 6:46:51 PM

Archived from groups: comp.sys.laptops (More info?)

I bought a stack of laptops at an auction which contain li-on batteries.
Half of them charge up to full and seem alright; the others refuse to
charge at all (in fact, I get the dreaded "red X"), leading me to
believe that they were simply left in the notebooks so long that their
polarity has reversed.

Is there any procedure or device which can fix this? (It'd be well worth
it even if it only worked on a percentage of the batteries.)

--
Reply to mike1@@@usfamily.net sans two @@, or your reply won't reach me.

Drug smugglers and gun-runners are heroes of American capitalism.
-- Jeffrey Quick
Anonymous
a b D Laptop
July 1, 2004 10:07:49 PM

Archived from groups: comp.sys.laptops (More info?)

Mike1 wrote:
> I bought a stack of laptops at an auction which contain li-on
> batteries. Half of them charge up to full and seem alright; the
> others refuse to charge at all (in fact, I get the dreaded "red X"),
> leading me to believe that they were simply left in the notebooks so
> long that their polarity has reversed.
>
> Is there any procedure or device which can fix this? (It'd be well
> worth it even if it only worked on a percentage of the batteries.)

Lion batteries that fail to charge are....dead. What you have is
possibly failure from being discharged to a very low voltage while the
computers were unused if there was slow current drain. This leads to
corrosion of the electrodes and that leads the inability to recharge the
battery. AFIK, because of the perceived dangers inherent in Lion
batteries, there is no consumer mode available for repairing a single
damaged cell in a battery pack.

Q
July 2, 2004 8:21:12 PM

Archived from groups: comp.sys.laptops (More info?)

In article <edWdnRIq9v_EOnnd4p2dnA@comcast.com>,
"Quaoar" <quaoar@tenthplanet.net> wrote:

>Mike1 wrote:
>> I bought a stack of laptops at an auction which contain li-on
>> batteries. Half of them charge up to full and seem alright; the
>> others refuse to charge at all (in fact, I get the dreaded "red X"),
>> leading me to believe that they were simply left in the notebooks so
>> long that their polarity has reversed.
>>
>> Is there any procedure or device which can fix this? (It'd be well
>> worth it even if it only worked on a percentage of the batteries.)
>
>Lion batteries that fail to charge are....dead. What you have is
>possibly failure from being discharged to a very low voltage while the
>computers were unused if there was slow current drain. This leads to
>corrosion of the electrodes and that leads the inability to recharge the
>battery. AFIK, because of the perceived dangers inherent in Lion
>batteries, there is no consumer mode available for repairing a single
>damaged cell in a battery pack.


I'm not seeing any "corrosion". My hunch is that weak polarity-reversal
is simply triggering some code flag to not try to recharge the battery
(thus the red-X as opposed to a "charging" zign that never goes above
0). If there was a way to flip the polarity back to normal, they'd
probably charge fine.

--
Reply to mike1@@@usfamily.net sans two @@, or your reply won't reach me.

Drug smugglers and gun-runners are heroes of American capitalism.
-- Jeffrey Quick
Anonymous
a b D Laptop
July 2, 2004 9:58:30 PM

Archived from groups: comp.sys.laptops (More info?)

Mike1 wrote:
> In article <edWdnRIq9v_EOnnd4p2dnA@comcast.com>,
> "Quaoar" <quaoar@tenthplanet.net> wrote:
>
>> Mike1 wrote:
>>> I bought a stack of laptops at an auction which contain li-on
>>> batteries. Half of them charge up to full and seem alright; the
>>> others refuse to charge at all (in fact, I get the dreaded "red X"),
>>> leading me to believe that they were simply left in the notebooks so
>>> long that their polarity has reversed.
>>>
>>> Is there any procedure or device which can fix this? (It'd be well
>>> worth it even if it only worked on a percentage of the batteries.)
>>
>> Lion batteries that fail to charge are....dead. What you have is
>> possibly failure from being discharged to a very low voltage while
>> the computers were unused if there was slow current drain. This
>> leads to corrosion of the electrodes and that leads the inability to
>> recharge the battery. AFIK, because of the perceived dangers
>> inherent in Lion batteries, there is no consumer mode available for
>> repairing a single damaged cell in a battery pack.
>
>
> I'm not seeing any "corrosion". My hunch is that weak
> polarity-reversal is simply triggering some code flag to not try to
> recharge the battery (thus the red-X as opposed to a "charging" zign
> that never goes above 0). If there was a way to flip the polarity
> back to normal, they'd probably charge fine.

Sorry, I wasn't specific: the corrosion is internal, not external.
There really is nothing that can be done with a Lion that won't charge.

Q
!