Yeah, I need this to take less than a second.  That way I can intelligently
determine what current to charge the pack with.  If you have a pack with a
2Ah capacity, then you can charge it at C, but if you have a 6Ah pack, then
it needs to be charged at 3C (C w/ respect for the 2Ah pack).



On 12/23/05, Anand Dhuru <ardhuru@vsnl.com> wrote:
>
> A long time ago, I'd seen a good idea for this requirement; basically, the
> pack was loaded; also the battery was used to derive a 1.5 (approx.)
> supply
> for an analog clock.
>
> How long the clock ran would give you an idea of the battery's capacity.
> Of
> course, this might not good for absolute ma-hour values, but was very
> convenient for comparing batterries, as in this case.
>
> Regards,
>
> Anand
>
>
> ----- Original Message -----
> From: "Shawn Wilton" <black9@gmail.com>
> To: "Microcontroller discussion list - Public." <piclist@mit.edu>
> Sent: Tuesday, December 20, 2005 4:43 AM
> Subject: [EE] Detecting/Calculating battery capacities
>
>
> > I've been googling for how to detect the difference between a 3(series)
> > cell
> > lithium pack and a 9(3x3) cell lithium pack.  Both supply 11.7 Volts.  I
> > haven't found anything useful yet.
> >
> > I was thinking maybe create a dummy load, with a sense resistor and
> > determine how much current the pack would kick out, but that doesn't
> seem
> > to
> > give a different value across the packs.
> >
> > Any ideas you guys care to share?
> > --
> >
> >
> > Shawn Wilton (b9 Systems)
> > http://black9.com <http://black9.net>
> > --
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--


Shawn Wilton (b9 Systems)
http://black9.com
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