Hagbard Celine wrote:
When it came to the battery part of the article there was still
nothing on an specific NiMH or LiLon batteries. I was wondering if
anyone has tried either of the batteries from this company:
http://www.atsipowermanagement.co.uk/lynx.html 10 A/H in a PS1270 size
would be nice if it works.

It looks like it would be a good choice, but I was unable to find a
supplier or cost. You would have to buy it's charger, also, so the total
cost for this "aviation" battery might be breathtaking. Let us know if
you do find a supplier. It still might be a good option for some people,
even if it is costly.

If you use a Trig TT21, the power drain should be low enough that a 4 to
5 ah battery would be adequate - not ideal, but adequate for 8-10 hour
flights in cold weather. That size is small and light enough, almost
everyone should be able to mount a battery just for the transponder, if
needed. Pilot reports on the Trig power consumption, anyone?

On Page 15 of the article, I detail why I do not recommend Li batteries
for gliders. Here's what I say:

" IF you can find a 12 to 14 volt, commercially produced lithium battery
pack, AND rated for operation to 18,000’ (or your
highest operating altitude) AND with a matching charger, THEN you might
consider using it. I couldn’t find any that met all these conditions
(Dec. 2007), the best matches I could find cost several hundred dollars,
and they wouldn’t fit a standard glider battery mounting."

If you use a battery ONLY for the Trig TT21, you don't need to have a 12
volt battery. It could be up to 30 volts. That relaxed voltage
specification might make it easier to find a suitable nimh or Li
battery. Still, the standard lead acid battery works well, it's cheap,
it's easy to charge, and it's safe. The weight isn't really an issue in
most cases, given the 500+ pound weight of a glider.

--
Eric Greenwell - Washington State, USA (netto to net to email me)

- "Transponders in Sailplanes - Jan/2010" also ADS-B, PCAS, Flarm tinyurl.com/yg76qo9

- "A Guide to Self-launching Sailplane Operation Mar/2004" Much of what you need to know tinyurl.com/yfs7tnz