🚀 go-pugleaf

In article <BzD705.C94@zoo.toronto.edu> henry@zoo.toronto.edu (Henry Spencer) writes:
>In article <1992Dec15.103954.6299@quando.quantum.de> henigan@quando.quantum.de (Kevin Henigan) writes:
>>I believe you can tell how full a nicad is from it's Voltage...
>
>No, you can't.  This is one of the fun problems of building a NiCd charger.
>The output-voltage curve of a NiCd is essentially flat from pretty nearly
>full charge to pretty nearly empty.

There are many applications where knowing the charge on the battery is 
crucial.  Given my rudimentary knowledge of electrochemistry, it would
seem that one could provide a third electrode on a battery, of some other
materials than the main electrodes, designed to indicate the balance of
electrolytes in the cell.  It might even be possible to detect battery
health as well as charge.  I could imagine building a really cheap IC
that could measure the pulsed characteristic curves of this third electrode,
and give a readout of battery condition, or control information to a charger.

Any electrochemistry buffs out there who can comment intelligently?

Keith
-- 
Keith Lofstrom         keithl@klic.rain.com       Voice (503)-520-1993
KLIC --- Keith Lofstrom Integrated Circuits --- "Your Ideas in Silicon"
Design Contracting in Bipolar and CMOS - Analog, Digital, and Power ICs