On Sun, 06 Feb 2011 16:37:34 +0000, Baron
wrote:


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.


Ah. I envisioned a unit that the battery was placed into rather than a
connector on a flying lead.

Understood as that's how yer typical charger works. The fact that this
charger is supposed to cope with near 'all' Dell batteries with the
one connector and many other makes with different connectors made it
all the more interesting. Apparently, if you get the connector on this
model reversed (we were only talking about the Dell batteries at the
time) nothing happens (good or bad). The previous model would release
pixy smoke from somewhere. The guy also ok'd the idea of being able to
supply the different ends as required and as available for about a
fiver each.

When you power it up you get a single red LED on the (sealed) power
'brick'. Plug it into a (good) battery and the 4 green LEDs light up
in sequence then extinguish (2 second cycle). Once the battery reaches
20% the first LED stays on and the remaining 3 cycle etc etc. It took
about 4 hours to bring this 1535 batter from 0% to 90 or so was about
3.5 hours so I imaging the charge current might be quite low (I don't
mind that).

I would be interested in the pin out for
that. :-)

Well there is a 4 pin plug that goes into the brick and another 4 pin
bigger connector in the middle of the short lead to the battery plug.
The next time I get the DMM out .. ;-)

Similarly (and as much use I guess) would be the pinout of the cells
to the connector, if I get to pull a pack apart?


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 !

Part of my doing all this is because (mostly) I like to understand
what's going on behind the scenes (a classic being that Youtube 1 Wire
power adaptor tutorial).

The battery packs that I've taken apart have not
had, what I would call "dead Cells" !

Exactly? ;-(

Usually there is one or two
cells that have very low voltages compared to the others.

[1]

I have tried
to boost the voltage on the low ones without disconnecting the others,
and found that they recover just fine.

We would call that 'balancing' in the RC model racing game. ;-)

Even so the pack still will not
charge though it will power the machine as normal.

Oh. So there may be summat 'deeper' going on here. Like with some
printers when they reach their nominal max print run limits?

Beyond that I've
not really had the inclination to investigate further.

I would if there was some logic and low cost to the process. Like if I
was given a batch of known good cells and a few battery packs to strip
down. Other than that it means a bit of gambling buying new cells and
we aren't really in a position to do too much of that right now.

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

It can be done, sometimes. ;-)

Cheers, T i m

[1] I have 6 'consumer' NiMH 'D" cells (that feel like they are AAs in
a 'D' size case .... and probably are) and four of them are currently
in our automatic kitchen rubbish bin lid mech. ;-)

I did start going through the 6 cells with Ah measuring recycler but
'she' needed this working. So, as the lid goes flat I'm measuring the
lowest voltage cell and replacing it with a known good one in the hope
I'll end up with the best matched set. ;-)