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[Fwd: [GPSL] Li ion Batteries]

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  • Mike Manes
    Hi Mark, Thanks for the treatise. I m cc ing Bill on this as well. His cell phone w/ Li ion died during first call of the AM at EOSS-72 (cold!!). And glad to
    Message 1 of 1 , Dec 21, 2003
      Hi Mark,

      Thanks for the treatise. I'm cc'ing Bill on this as well. His cell
      phone w/ Li ion died during first call of the AM at EOSS-72 (cold!!).

      And glad to get a confirmation on the LiSO2 -- I guess .... BTW,
      since those priamry cells do dissipate a bit in the internal
      resistance under load, I rather doubt they'll ever see -40C during
      a typical balloon flight while they're loaded. The LiSO2 cells
      most likely to "chill out" are the one I use to fire the cutdown
      burner wire - they're unloaded except when burning, and are carried
      in a 0.33" thick foamcore box inside the parachute canopy. But I can
      get over ten 10-sec 4+A burns out of 'em.

      Guess if I go to Li-ion, it'll take a cold-soak and flight qual
      before I rely on 'em. Oh, and maybe the Li polymers will perform
      better ...

      73 de Mike W5VSI

      Mark Conner wrote:
      >
      > http://www.batteryuniversity.com/partone-15.htm
      >
      > "At low temperatures, the performance of all battery chemistries
      > drops drastically. While -20°C (-4°F) is threshold at which the
      > nickel-metal-hydride, sealed lead-acid and lithium-ion battery
      > cease to function, the nickel-cadmium can go down to -40°C
      > (-40°F). At that frigid temperature, the nickel-cadmium is
      > limited to a discharge rate of 0.2C (5 hour rate). There are new
      > types of Li?ion batteries that are said to operate down
      > to -40°C."
      >
      > Note that the old heavy NiCd's are the best for cold performance
      > among the rechargeables.
      >
      > LiSO2 still operates at -40°C but also at reduced capacity.
      > http://voltaicpower.com/Batteries/high-disch-lith.htm
      >
      > I have some lithium-polymer batteries that I'll be testing for
      > the NSTAR payload in the next few weeks, to replace the NiMH pack
      > currently in use. The testing will include some cold performance
      > tests.
      >
      > 73 de Mark N9XTN
      >
      > ----- Original Message -----
      > From: "Mike Manes" <manes@...>
      > To: <GPSL@yahoogroups.com>
      > Cc: "Bill Beach K0UT" <k0ut@...>
      > Sent: Sunday, December 21, 2003 15:13
      > Subject: Re: [GPSL] Li ion Batteries
      >
      > > Hi Paul,
      > >
      > > Bill K0UT tells me that Li ion batts don't share the low-temp
      > tolerance
      > > of LiSO2 cells. And in fact, they may be less tolerant of cold
      > than
      > > NiMH.
      > >
      > > If you get some, could you do some cold-soak capacity tests?
      > I'd sure
      > > like to get away from the tedious task of replacing payload
      > batts for
      > > every flight and adding to what has become a rather large mound
      > of
      > > used LiSO2 cells!
      > >
      > > 73 de Mike W5VSI
      > >
      > >
      > >
      > > paul.verhage@... wrote:
      > > >
      > > > All Electronics is selling 1200 mah li ion batteries for cell
      > phones for $6.50. the
      > > > recharger is $4.50. I was able to solder wires to the
      > battery and wrap in it heat
      > > > shrink. I also shorted the two metal spring plates inside
      > the recharger and soldered
      > > > wires to them. This way I could terminate the battery in a
      > connector for my near
      > > > spacecraft and still recharge them.
      > > >
      > > > Li ion are nice because they don't suffer from memory effect
      > and can handle low
      > > > temps.
      > > >
      > > > Paul
      > > >
      >
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      --
      Mike Manes manes@... Tel: 303-979-4899
      "Things should be made as simple as possible, but not more so." A.
      Einstein
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