Anybuddy know the R-value of ski pants?

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From here:
http://carbonpig.com/article/electr...environmental-impact-and-life-cycle-batteries

Electric Cars Don't Use Fossil Fuel, but what's the Environmental Impact and Life Cycle of the Batteries?
By Matt Oden 01/21/2010

"Many of us have experienced that dead cell battery in your ski pants; move it into your underwear for awhile and wahla - your battery works again for a little bit."

Anywhooo... subject is battery container insulation for freezing temps... I've written these folks to ask if I can buy a sample size of one of their aerogels:
http://www.aerogel.com/

Some aerogel looks like this:


The stuff from Aspen looks more like this:


One nice thing about the Aspen product is ya get an R-Value of 10 for a sheet that's only 5mm thick. And it's flexible, can be cut with scissors. Another plus might be that it's rated to handle up to 650C/1200F so might serve to help contain some out-of-control lithium someday...

Anyway, we'll see. This is for wrapping up a 48V 10Ah LiFePO4 pack and provide vibration dampening as well as cold weather insulation.
tks
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[northernmike]

wow, good idea, man. planning to heat too? or just indoor charging / storage?

 

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I plan to slide a couple of heaters under the pack, seen here:
http://www.endless-sphere.com/forums/viewtopic.php?f=14&t=15183#p225497

In that thread thomas figures each heater is good for only 14W connected to 48V DC pack voltage, so I figure the best approach is to keep the heat in. (Steveo pointed out nitrous bottle warmers but they seem a little TOO watt-intensive...) Manual on/off switch but also a thermostat to switch the heaters on if internal pack temp drops to 10C temp or below. In that same thread, turns out if the cells are on the chilly side the 480Wh pack might be putting out a few dozen watts in normal discharging as well. Then there's the option (maybe) of plugging the heaters directly into 120VAC to goose their warmth up to 35W each...

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[Lock]

Here is the data sheet:
http://www.aerogel.com/products/pdf/Pyrogel_XT_DS.pdf

I have probably misunderstood its correct R-value, but as best I can understand per inch it is about twice as good as Thinsulate(TM). And per the data sheet "Hydrophobic Yet Breathable"
tks
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[Lock]

BTW, this stuff will work out to about $12 a square foot. Min.order quantity is 24 sq.ft and I don't need that much... so if any cold weather folks are interested in this 10mm thick insulation lemme know. I'm talking about the Pyrogel XTF flavour of aerogel which as an added bonus is fire rated up to 650 degrees Celsius... which may be of interest to folks playing with various lithium chemistries (grin)

Or you can just use yer ski pants...
tks
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