Victor Tikhonov wrote:
>
> Having constant voltage source by itself is no guarantee
> against overheating/overcharging.
>
> You don't necessarily need a charger per cell, but you do need
> at least a thermal sensor on each cell.
>
> All the sensors should talk to the charger.
>
> 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.
>
> 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).
>
> Also combining tracking Ah in/Ah out with dT/dt should
> be sufficient as well.
>
> 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...
>
> 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.
MK3s at least, maybe the MK4 with multi cell scanning.
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.
--
Rich Rudman
Manzanita Micro
www.manzanitamicro.com
1-360-297-7383,Cell 1-360-620-6266
