On Apr 24, 1:28*pm, Marc Ramsey wrote:
wrote:
Sorry, didn't mean to start an argument. Maybe my caution regarding
flying with R/C (foil bag) LiPo batteries is a little over the top. I
can live with erring on the side of caution. To each his own.

I'm not trying to get into an argument either, just making the point
that most of us already carry several foil bag lithium polymer batteries
in our gliders. *The original metal case lithium ion batteries haven't
been used in consumer products for years, mostly because we want
everything light (remember 8 lb laptops?).

R/C batteries have a high (explosive 8^) failure rate mostly due to the
various kinds of abuse they are subject to, incorrect charging,
continued use after being damaged in crashes, overly high discharge
rates, full short circuits, etc. *If someone knows what they are doing,
there shouldn't be a problem. *But, I agree, if you don't know, don't do
it. *I, for one, wouldn't want a pack large enough *to power a radio and
transponder in my glider...

Marc

I have done the RC thing for over 45 years. I've observed that as the
use of LiPo cells have progressed the rate of failure has decreased.
Inspite of that I would also either use a metal cased cells or a pack
in a metal box if I were to use them in an aviation application.
Istalled in the PDA or Cell phone they have some puncture protection
and that seems to be one of the major hazards to their use.

On the same idea; the A123systems cells are metal cased and at $110
for six (2.3 Ah) of them is a pretty good deal as far as lithium cells
go. I'm planning on getting several "Developer Kits" to assemble
several packs for the glider. Four cells, each a little larger than a
AA Alkaline, means that I can get a pretty good serial/parallel
battery setup and fit the individual battery packs into small
spaces.

The BIG handicap is the cost; to assemble 3 packs will cost $220 plus
assembly and wiring, for a 7.2AH pack.