Unfortunately, Chrisant, it is not possible with the current technology.
Since answer depends on actual values, let's get quantitative.
Bear with me, it will be simple:
I weighed a small hair dryer and got 300 grams. (Its power is 1600W)
Then I weighed a decent NiCad battery. It was 320grams (Sharp video camera)
Thus this battery, if built-in, would double the weight and make the dryer
quite heavy (620grams = 1.3 pounds)
So, it would last about 4 Ah / 200 A = 3600 * 4 s/ 200A = 36 * 2 seconds
Thus for this hairdryer, the battery would go dead in 72 seconds.
This will give you some idea how much power heater-type appliances use.
Your quest for a cordless pre-chargeable re-chargeable hair dryer for camping
looks like it will be a long time in coming. Sorry about that.
We did not consider case of having a battery on a belt (connected by cord)
or using very expensive Lithium battery. I guess we still would not make it
(but we could try to check that option (as a new question, I would hope))
Hedgie
PS. to convert grams (g) to ounces, just type into a (good) search engine
620 g in ounces
to get
620 grams = 21.8698564 ounces
like this
://www.google.com/search?hl=en&q=620+g+in+ounces&btnG=Google+Search
620 grams = 21.8698564 ounces
620 grams = 21.8698564 ounces |
Clarification of Answer by
hedgie-ga
on
19 Sep 2005 18:26 PDT
Interestingly enough, if you go for Lithium batteries, you may be just
able to squeeze your specification in. Cost was not specified as factor!
This is area of active research (batteries for the electric cars)
and so considerable progress is expected next decade.
You need to differentiate between
1) Lithium battery (no-recharge, throw-away (meaning recycle! :-)
with- high cost per use and very light.
2) Lithium Ion battery, more expensive to buy, but less expensive per use.
For case 1) you can get battery storing 1kJ having mass of 1g for $.15 see
http://www.mouser.com
for actual batteries, one can buy today.
To operate 1200W appliance for 3 minutes you need 216 kJ of energy
That translate into a battery with mass of 216 g at cost of $32 per use.
In 10 years, that picture may improve:
"..lithium battery is not rechargeable and should never be recharged,
while lithium-ion batteries are designed to be recharged hundreds of
times..."
http://www.carlist.com/autonews/2005/autonews_188.html
Costs of Lithium-Ion Batteries for Vehicles:
"..current and projected cost estimates for lithium-ion batteries,
as a function of materials ... total mass of the battery pack is 364 kg
(just under 800 lb), ..." (this is for electric cars)
"expected cost for future electric car batteries "
hi-energy $250/cell $20/cell for a typical 100A h cell
http://www.transportation.anl.gov/pdfs/TA/149.pdf
The science behind these numbers (namely why Lithium is 'best' ):
having 41 kJ per gram storage density, as a theoretical limit:
http://www.chemsoc.org/chembytes/ezine/2000/toolkit_mar00.htm
So, there is hope: Help is on the way.
Hedgie
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