[PLUG] technical circuit diagnosis

[wes]

You are correct, those are very interesting points. If your understanding of
the connector is correct, you should be able to recondition the cells
individually. Or, if you can use a tester to find the bad one, just
recondition that one.

If it's less than a year old, I would suspect a manufacturing defect in the
battery. Wouldn't be the first time...

-wes

On Wed, Jun 3, 2009 at 3:46 PM, Eitan Tsur <eitan.tsur at gmail.com> wrote:

> The interesting thing is A: this is a new battery, bought last year, when I
> acquired the laptop as a gift.  B: I have a PII (yes, that's a 2)-era
> laptop
> made by HP that still works perfectly.  C: I've used my R/C li-ion/li-poly
> charger and balancer on totally dead packs before and they come back to
> almost full life again.  As soon as I find an appropriate header I plan to
> do the same for these.  It's interesting because the battery packs for this
> laptop seem to be controllerless.  (connector off pack has taps from each
> cell pair).  Usually from what I've seen most commonly from other laptops
> in
> the past is that the cell pairs get unbalanced, which causes charging to
> shut off prematurely.  In this case it's just not charging at all.
>
> On Wed, Jun 3, 2009 at 2:40 PM, wes <plug at the-wes.com> wrote:
>
> > For a 10 year old laptop, it will likely be much faster/easier (not to
> > mention cheaper) to find another of the same model on ebay, maybe with a
> > broken screen, and swap parts, than it would be to actually repair the
> > circuitry on the board.
> >
> > I understand the reasoning behind not just getting a different model
> > altogether, but 10 years is really pushing the limits of laptop life
> > expectancy. I am on my 3rd Latitude D800 (with parts from the first 2
> still
> > going) and am about to start looking for my 4th parts donor....
> >
> > All that said, it is far more likely to be the battery itself as Joe
> Pruett
> > stated. This is just based on my experience.
> >
> > Since you have a spare battery, this should be very easy to test.
> >
> > -wes
> >
> > On Wed, Jun 3, 2009 at 2:03 PM, Eitan Tsur <eitan.tsur at gmail.com> wrote:
> >
> > > I have a ~10(?) year old laptop that has recently stopped charging it's
> > > battery.  (few days ago it stopped charging past ~30%, ran on battery
> for
> > 5
> > > minutes, laptop died, now shows 0% charge).  Does anyone know what the
> > > first
> > > step would be to diagnose this issue?  Laptop itself powers up just
> fine
> > on
> > > wall power, and I have a spare battery I can try to verify it isn't a
> > blown
> > > fuse or something in this pack.  If I can find a 7 pin 2mm pitch header
> I
> > > plan to hook up my li-ion charger/balancer to the pack to recharge,
> > however
> > > I fear the charging circuit on the motherboard may have gone out.
> >  Assuming
> > > this is the case, does anyone have the knowledge or experience to
> > > diagnose/repair this?  I've done SMD rework before, but circuit
> > > design/reverse engineering/testing is beyond me.  Any advice will be
> > > appreciated.
> > >
> > > regards,
> > > -Eitan Tsur-
> > > _______________________________________________
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> > > http://lists.pdxlinux.org/mailman/listinfo/plug
> > >
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