T i m Inscribed thus:

On Sat, 05 Feb 2011 21:03:07 +0000, Baron
wrote:

They put these "one wire" interfaces into the batteries too !

No, really? ;-(

So I understand.

Ok ta. I've asked on the Dell n/g if anyone can confirm if this
particular model / generation does so for sure, just in case it could
be summat else.

Good move !

I've had cheap Chinese made ones that wont charge in a Dell !
Which sounds a bit like the one you refer to above.

It does indeed. However, after Googling about it seems there may be
some hope in a BIOS update? It's currently A2 and I think there is
an A5 or 6 to be had. I just need a charged battery in there to do
it. I've ordered an external charger as I'm told the pinout of most
of the Dell batteries are the same

Yes but they put the connector block in different places on the
battery pack !

Yeah but this charger is what I would call more of a tech / service
aid as the charging plug is floating on the end of a wire and (can be)
held against the battery with a Velcro tie. This morning I used it to
charge the battery from the Studio 1535 (and therefore was able to
apply the BIOS update) and currently I'm seeing if it can wake up the
old battery from daughter D510 Latitude (only to see if I / it can,
I'm pretty sure it's pretty low capacity now).

Ah. I envisioned a unit that the battery was placed into rather than a
connector on a flying lead. I would be interested in the pin out for
that. :-)

You will have to let me know how it goes.

So far I'd say pretty well, insofar as it has allowed me to update the
BIOS and prove an unknown battery to be good even if not compatible
with the laptop. ;-(

(so it will cover a fair range of models
and we have a few between us) in case I can't access another machine
or a charged battery elsewhere.

Might as well do the easy / non-invasive things first. ;-)


I couldn't agree more.

This 1 Wire stuff may well be there for good reason (?) but when
charging up old laptops with basic two wire connections and NiCd/NiMH
they just charge, even if they only last for 5 mins (enough time to
act like a UPS). If they don't a bench PSU might get you started ...
sigh

I'm now looking to see if I can borrow a battery for the 1535 before I
suggested they buy 'another/ batter but at least this time we will
know what questions to ask. ;-)

Cheers, T i m

p.s. I was wondering just how the original Dell battery declared
itself 'dead' and therefore, if I was to re-cell the original with the
cells from the clone, will it be happy (or have the electronics now
shut down for good)?

I'm not at all sure ! The battery packs that I've taken apart have not
had, what I would call "dead Cells" ! Usually there is one or two
cells that have very low voltages compared to the others. I have tried
to boost the voltage on the low ones without disconnecting the others,
and found that they recover just fine. Even so the pack still will not
charge though it will power the machine as normal. Beyond that I've
not really had the inclination to investigate further.

As an aside I have a set of recovered cells happily powering an alarm
bell, float charged from the regulated 12V supply.

--
Best Regards:
Baron.