[amsat-bb] Ni-Cd's on Satellites and MASS advantage!

[Mike Wilhelm]

Stumbled on this paper by accident:

http://adsabs.harvard.edu/full/1998ESASP.416..715C

-Mike

On Sat, Mar 14, 2020, 10:02 PM Jerry Buxton via AMSAT-BB <amsat-bb at amsat.org>
wrote:

> Amen.
>
> Jerry Buxton, NØJY
>
> On 3/14/2020 11:53, Robert Bruninga via AMSAT-BB wrote:
> > We have used NiCds on all of my 4 satellites with no battery problems.
> >
> > They are robust, and survive all student mistakes and require no Battery
> > management system when paired with a matching solar panel design.  IE, as
> > th batteries approach full charge is the same point where the solar panel
> > voltage maxes.  Also NiCd's can be safely overcharged at 10% indefinitely
> > with no concern. (you only get an hour in the sun and then 35 minutes
> > eclipse)...
> >
> > Yes, they are twice as heavy as Lithium, but the advantages FAR outweigh
> > the criticality of Lithium concerns and complexity of the BMS and total
> > failure on overcharge or undercharge.
> >
> > And MASS is an advantage!   PSAT and BRICSAT-1 are identical 1.5U
> cubesats
> > launched at the same time in May 2015.  But PSAT with big C cell NiCd's
> was
> > made heavier with lead ballast to 2.3kg.  BRICSAT (1.7 kg) with
> lightweight
> > Lithiums has already decayed in November.  PSAT is predicted to last 2
> more
> > years!  Same thing for identical RAFT and MARSCOM cubesats back in 2006.
> > RAFT was ballasted up and lasted TWICE as long as MARSCOM.
> >
> > For comm satellites, there is no reason to come in under mass.  Always
> > ballast up  to the maximum the launcher will allow!
> >
> > Bob, WB4APR
> >
> >
>
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