Mountain High EDS O2 system battery

From my personal observation at FL235 and the temperature minus 26C the unit
slowed down and then failed I put the EDS onto emergency supply.

Note the steep descent after this moment LOL
http://www.mals.net/bunyan04/pages/Picture%20001.htm

In future if I go above FL180 I will have a spare battery and a battery
inside my clothing (32C degrees is about optimum battery operation body temp
is 36C) with wires and connectors coming out to connect to the EDS unit.

I will also carry a spare or emergency oxygen system.

As simply having the battery in the pocket of the glider exposes the battery
to the cold temperatures so its just as useless.

Think of another thing its freezing cold you take your hands out of the
gloves you then have to fumble with the battery and fly the glider.

Remember if you smoke at ground level you are already at 5000FT

The hypoxia curve is worth a study as well.

Is adrenalin part of the discharge curve LOL

Is there any documented discharge curve for these styles of batteries at
sub zero temps ? ....(eg) high altitude wave flight


--
keithw
------------------------------------------------------------------------
Posted via OziPilots Online [ http://www.OziPilotsOnline.com.au ]
- A website for Australian Pilots regardless of when, why, or what they
fly -

"In future if I go above FL180 I will have a spare battery and a
battery
inside my clothing (32C degrees is about optimum battery operation body
temp
is 36C) with wires and connectors coming out to connect to the EDS
unit.
I will also carry a spare or emergency oxygen system.
As simply having the battery in the pocket of the glider exposes the
battery
to the cold temperatures so its just as useless.
Think of another thing its freezing cold you take your hands out of the

gloves you then have to fumble with the battery and fly the glider."

Point(s) well made.

So far my O2 experience has been up to FL180. Certainly going far above
that brings forth other serious considerations. I have thought I would
install a continuous flow system as a back-up to the EDS if, and when I
decide to fly at those altitudes. Then also a spare/emergency?

Do you have any special considerations for the glider primary batteries
when it gets that cold?

"Go" wrote in message
oups.com...
So far my O2 experience has been up to FL180. Certainly going far above
that brings forth other serious considerations. I have thought I would
install a continuous flow system as a back-up to the EDS if, and when I
decide to fly at those altitudes. Then also a spare/emergency?

Do you have any special considerations for the glider primary batteries
when it gets that cold?


I think it depends on how long exposed as well as how cold. The ship's
lead-acid batteries have a fair amount of mass, so internal temperatures
will drop more slowly than some other stuff in the glider. Obviously,
battery location plays a role too, i.e. it's typically warmer in the cockpit
than elsewhere. Since the batteries are discharging and have some internal
resistance, the internal power dissipation also adds warmth. That said,
battery capacity at freezing will be down some 20% or more, and at -22F,
down 50%.

I understand Stemme insulated their battery installation for the wave
flights in S. America several years ago.

bumper
ZZ Minden, NV

Yes the glider batteries were packed by some pilots in foam etc.

I have also pack the baggage compartment with a spare fleece or two less air
mass to cool down and it insulates the area as well.


"bumper" wrote in message
...

"Go" wrote in message
oups.com...
So far my O2 experience has been up to FL180. Certainly going far above
that brings forth other serious considerations. I have thought I would
install a continuous flow system as a back-up to the EDS if, and when I
decide to fly at those altitudes. Then also a spare/emergency?

Do you have any special considerations for the glider primary batteries
when it gets that cold?


I think it depends on how long exposed as well as how cold. The ship's
lead-acid batteries have a fair amount of mass, so internal temperatures
will drop more slowly than some other stuff in the glider. Obviously,
battery location plays a role too, i.e. it's typically warmer in the
cockpit than elsewhere. Since the batteries are discharging and have some
internal resistance, the internal power dissipation also adds warmth. That
said, battery capacity at freezing will be down some 20% or more, and
at -22F, down 50%.

I understand Stemme insulated their battery installation for the wave
flights in S. America several years ago.

bumper
ZZ Minden, NV