[amsat-bb] Re: Lithium polymer batteries

[Michael Tondee]

-------- Original Message --------
Subject: 	Re: [amsat-bb] Lithium polymer batteries
Date: 	Thu, 24 Jun 2010 12:34:14 -0400
From: 	Michael Tondee <mat_62 at netcommander.com>
To: 	amsat-bb at amsat.org



  Li poly batteries are perfectly safe as long as one uses common sense
and follows basic safety procedures. The fire retardant bags and clay
pots are a nice extra bit of insurance but I haven't found them really
necessary as long as I pay attention.
  I charge my batteries outside mostly or if I do charge them inside I
don't leave them unattended. As someone already stated, using the proper
charger is the key. With the proper state of the art charger it is near
to impossible to overcharge a li poly battery. I emphasize "state of the
art". A very good one called the Cellpro is made by a company named FMA
and is under $100 in price.
  I fly electric RC airplanes and helicopters with Li poly batteries. I
order them online and I have never been charged any type of hazmat fee.
FWIW I've had numerous hard crashes  with my heli and have never ever
had a li poly battery explode or catch fire.
  These batteries have revolutionized RC flying. Along with brushless
motors, it's a whole new world. It's now possible to fly planes of the
size that used to take nitromethane or "glow fuel" powered engines with
clean quiet electric power.
73,
Michael, W4HIJ
On 6/24/2010 10:01 AM, whiteld at usa.net wrote:
>  Following up on the Lithium polymer battery mention I Googled them and was
>  disturbed to find:
>
>  -high fire risk. One seller offers flame retardant bags to put the cells in
>  while charging them... for $25
>
>  -(as warned) high prices especially considering the more-unique balanced
>  charger / discharger devices at ~$100 and up being required in addition to the
>  cells themselves
>
>  -a hazardous materials uplift for FedEx shipment ranging from $25-$45
>  depending on destination, on top of normal shipping rates
>
>  All of that tells me they're "not ready for prime time" though the current
>  capacity vs weight looks very promising.
>
>  I will wait and watch, hoping the technology matures into something safer and
>  less costly as time goes on. Likely it will, particularly the cheaper part,
>  though it appears some safety issues have to be addressed meaningfully.
>
>  Thanks for the mention. It is interesting.
>
>  Lowell
>  K9LDW
>
>
>  _______________________________________________
>  S