Hi Rich, Victor and All,
--- Rich Rudman <[EMAIL PROTECTED]> wrote:
> Victor Tikhonov wrote:
> >
> > Having constant voltage source by itself is no
> guarantee
> > against overheating/overcharging.
Did I say that? I just said a source of power
for the cell charger-regs that actually do the
charging. Each cell, 1 regulator and/or charger.
> >
> > You don't necessarily need a charger per cell, but
> you do need
> > at least a thermal sensor on each cell.
You have to regulate each cell as the temp co-eff
is very large with small changes in temp making large
changes in charging safety.
If the Li-ion batt makers thought they could do
it by batt instead of cells, they would because it
would be cheaper, but they don't so I take that as a
hint.
> >
> > All the sensors should talk to the charger.
Yes they could but all they would need to do is
tell it when all were finished. Not very hard.
> >
> > Regarding charging profiles, they are developed
> and in fact
> > in many cases not that different from PbA alg,
> except
> > for thermal compensation and full charge
> detection.
Is that ALL? Isn't this the difference between
night and day?
> >
> > Consider this:
> http://www.thunder-sky.com/qxt/Curve-2.htm
> > They recommend simple CC/timed CV method
> (provided, you
> > monitor temp and compensate for it).
Don't they do it for each cell?
> >
> > Also combining tracking Ah in/Ah out with dT/dt
> should
> > be sufficient as well.
Not really because they thermal co-eff very so
much several cells would be either under or over
charged. Not Good.
> >
> > A charger better have downloadable (in
> non-volatile memory)
> > profile ability with programmable timers for each
> charging
> > phase. It has to have means to be throttled/shut
> off by
> > external sensors and optionally - by an Ah
> counter.
> > Not terribly complex, but bad boys are definitely
> out...
As above timers are useless on Li-ions. Times
very greatly depending on each cells temp.
> >
> > Victor
> >
> > jerry dycus wrote:
> > >
> > > Hi Bruce and All,
> > > Most Li-ion batts have a charger on each
> cell
> > > to keep it inside it's thermal limits. So just a
> > > constant voltage source should be all you need.
> > > jerry dycus
> > > --- Bruce EVangel Parmenter <[EMAIL PROTECTED]>
> wrote:
> > > > If li-ion batts become affordable and
> available, my
> > > > next
> > > > question would be
> > > > -what chargers have a charging algorithm for
> li-ion?
> > > >
>
> Bruce, Victor, Gary LIon dreamers ET al.
>
> It's real simple you screw up a Lion 100 amp hour
> cell and you need a
> Scatter shield.
> Over charge and you plate out metalic Lithium.. it
> soaks up O2 and
> starts a fire, BANG!.
> We will need Temp of each Cell, voltage of each
> cell, some mechanisim
> to shunt power around from a really full cell. And
> oh yea the system
> will need to know WHICH cell is in trouble.
Exactly what I said.
> MK3s at least, maybe the MK4 with multi cell
> scanning.
They would need to completely cut the charge
to higher temp cells to keep their temp from rising
more.
> The charger will need to have a fully programmable
> memory, and some
> really nifty temp and amp hour tracking and curve
> tracing.
> Even at this... the battery control system will be
> impressive.
It could be that just time to charge for each
cell history is all that's needed to find bad cells
with each cell charger taking care of keeping it in
temp, charge specs, ect.
jerry dycus
>
> --
> Rich Rudman
> Manzanita Micro
> www.manzanitamicro.com
> 1-360-297-7383,Cell 1-360-620-6266
>
__________________________________________________
Do you Yahoo!?
Faith Hill - Exclusive Performances, Videos & More
http://faith.yahoo.com
