Building a "Robinson Crusoe" Battery
Too_Many_Tools
I started considering what would one have to do to build a "Robinson
Crusoe" battery to power equipment in an emergency.
Assuming a battery of 12v and respectable current to power
communications equipment, how would you do it?
What materials would you use?
How would you charge it?
I look forward to your contributions.
TMT
Eric Sears
<too_man...@yahoo.com> wrote:
>Reading the thread on the Voltaic pile in sci.chem.electrochem.battery,
>I started considering what would one have to do to build a "Robinson
>Crusoe" battery to power equipment in an emergency.
>
>Assuming a battery of 12v and respectable current to power
>communications equipment, how would you do it?
I wonder what you envisage as "respectable"? I guess 0.5 to 2 amps
might be useful. You would certainly want to minimise power usage in
an emergency situation.
>
>What materials would you use?
>
>How would you charge it?
I guess it mostly depends on what you have available.
Your assumption seems to be a "rechargeable" battery - but I suspect
that a primary battery would be easier.
For a rechargeable - a lead cell would be simplest provided you can
find some. If you cannot get acid - sodium bicarbonate works tolerably
well (it works quite well in a number of cells and does not cause the
"chlorine" problems of cells that use salt solution as electrolyte).
Other than having a few solar cells lying around (there are heaps of
them in garden lights in NZ), you might need to rig up some sort of
hand-cranked generator.
Primary cells using large areas of "plate" could provide some current.
I would say use a plastic buckets for each cell, or something of
similar size. Two litre milk bottles with the tops cut off might be
big enough, provided you can stuff enough connected plates in each,
using paper or plastic seperators.
The most common materials for the plates might be aluminium and either
tin plate (food cans), or roofing iron.
However, in the end I suspect that unless I were cast away on a desert
island with no batteries, I would be endeavouring to FIND something
that already works. There are batteries in many items these days -
from cellphones to garden lights to toys.
Much more important is how to keep them charged. This is where a large
primary battery (supplying a small current at sufficient voltage),
could be used to charge the NiMH and other batteries that are commonly
found.
Just my tuppence worth.
Eric
boB_K7IQ
I have thought about this before. I would hope there was at least some
wire to hook up the battery.
How would you make wire ? Maybe this island has some metal of some
sort on it for both purposes.
boB
Rube
JR North
Shack's window and get all the batteries I need.
JR
--
--------------------------------------------------------------
Home Page: http://www.seanet.com/~jasonrnorth
philo
"Too_Many_Tools" <too_man...@yahoo.com> wrote in message
news:1136229191....@g49g2000cwa.googlegroups.com...
> Reading the thread on the Voltaic pile in sci.chem.electrochem.battery,
> I started considering what would one have to do to build a "Robinson
> Crusoe" battery to power equipment in an emergency.
>
> Assuming a battery of 12v and respectable current to power
> communications equipment, how would you do it?
>
> What materials would you use?
>
a "Robinson Crusoe" battery must be one you'd make if stranded on an
island...
so you'd have plenty of sea water.
you could use electrodes of copper and zinc
TimPerry
"philo" <ph...@privacy.net> wrote in message
news:Goednf0gfr8...@athenet.net...
get a bunch of coconut shells. place an electric eel in each. wire in
series. make odd numbered cells male eels and even numbered cells female
eels. that way you should have alternating currents :)
amdx
"TimPerry" <timp...@noaspamadelphia.net> wrote in message
news:GtmdndXKbej...@adelphia.com...
Dave Plowman (News)
philo <ph...@privacy.net> wrote:
> a "Robinson Crusoe" battery must be one you'd make if stranded on an
> island... so you'd have plenty of sea water. you could use electrodes of
> copper and zinc
Plenty of that on the average desert island...;-)
--
*It IS as bad as you think, and they ARE out to get you.
Dave Plowman da...@davenoise.co.uk London SW
To e-mail, change noise into sound.
meow...@care2.com
> In article <Goednf0gfr8...@athenet.net>,
> philo <ph...@privacy.net> wrote:
> > a "Robinson Crusoe" battery must be one you'd make if stranded on an
> > island... so you'd have plenty of sea water. you could use electrodes of
> > copper and zinc
>
> Plenty of that on the average desert island...;-)
I've been wondering that too. I'd likely pick salt water electrolyte
and carbon and steel electrodes. Assuming there is no ready metal on
the island, hopefully there would be a zip on some clothing, a button
or something. Burnt vegetation could provide the carbon.
I found a little 1" or so bottletop sized cell gave in the region of
half an amp at 1v. The electrodes corrode quickly, in a day.
NT
TimPerry
"amdx" <am...@worldnet.att.net> wrote in message
news:2dc55$43b9bfbc$18d6b488$19...@KNOLOGY.NET...
fix a 2 foot hole in a boat?
Tony Wesley
TimPerry wrote:
> how come the professor could make a thermopile out of coconuts but couldn't
> fix a 2 foot hole in a boat?
He could have fixed the boat but he didn't want to. He was hoping to
get somewhere with Mary Ann.
none
wrote:
Hey.. We All wanted to get some where with Mary Ann.(And damn if that
Dawn Wells doesn't look just as good today as she did then.)
phatty mo
I've been wondering along similar lines..
I've been wondering how I could make a reasonable ~12V battery,cheaply
and easily.
Maybe some saltwater cells,built up in Tupperware containers?
Assuming maybe 0.5V per cell,and (if they're large enough) perhaps 10AH?
24 containers in series,it would be fairly large!
If we can find some good electrode materials,the cell voltage may go
up,so we would need less cells/containers
Salt and water are both readily available,and pretty cheap,so the
electrolyte could be replenished easily enough...(any ideas for
something better,that's easy to get,and fairly cheap?)
But,I'm not sure what would be best to use as "plates",keeping the
cheap,and easy concept in mind.(They will eventually corrode away,right?)
Perhaps some kind of setup with pipes-inside-of-pipes.
Pehaps you could then build the cells up inside of some lengths of PVC?
4 inch diameter PVC,maybe 3-4 feet long,with a copper pipe inside of a
steel pipe,inside of the PVC pipe?
Keep a bag of salt next to it,and when the power goes out,dump some salt
and water in the cells,and turn on a (LED) light or something for a
while.. could be handy.
I recall seeing an "emergency battery" that used sea/salt water for an
electrolyte..apparently it went through electrodes quickly..
But it had a decent capacity,and was fairly small,maybe half the size of
a car battery?
But I've no idea what exactly they used for electrodes.
It could be useful to have a "backup" battery with an infinite shelf
life,untill you fill it.
Perhaps then you could just rinse it out,and store the electrolyte (or
not,saltwater is fairly non-toxic,shouldn't be an issue to dispose
of/dump.) and store it untill you need it again?
I'd actually like to build something like this,but at this point it's
just a half-thought bouncing around my brain.
If you have any ideas,I'd like to hear them!
peter
What about the water activated lights in lifejackets? Quite small,
aceptable current, but once wetted they can't be shut down; the cell
continues to degrade if disconnected.
meow...@care2.com
> I've been wondering along similar lines..
> I've been wondering how I could make a reasonable ~12V battery,cheaply
> and easily.
I've done just what you talk about, so can offer a few details on mine.
> Maybe some saltwater cells,built up in Tupperware containers?
Here you can buy flat multicompartment cases for £2, with 18 sections,
used for storing screws etc. These are ideal as long as you can keep
the thing horizontal while active. Tip it up and the water would run
between cells.
> Assuming maybe 0.5V per cell,and (if they're large enough) perhaps 10AH?
I think people are underestimateing here. I used an M3 bolt and a bit
of carbon, which will fit into a roughly 1" bottle cap, and got 1v 0.5A
all day. Thats 5Ah or more. So a multicompartment tray would provide
several times the Ah at 18v.
> 24 containers in series,it would be fairly large!
> If we can find some good electrode materials,the cell voltage may go
> up,so we would need less cells/containers
Well... the more V you want out, the faster it corrodes. Mine gave very
little out after 24hrs, but scraping the steel renewed it, so I'd go
for long service life as far as poss. I reckon one could easily improve
on steel as an electrode, but its free in large amounts.
> Salt and water are both readily available,and pretty cheap,so the
> electrolyte could be replenished easily enough...(any ideas for
> something better,that's easy to get,and fairly cheap?)
exactly
> But,I'm not sure what would be best to use as "plates",keeping the
> cheap,and easy concept in mind.(They will eventually corrode away,right?)
yes, thats the nature of batteries. The lower the whatnot of the plate
materials, the slower they corrode. So pick one plate as low as poss on
your electrowhatever it is scale, and the other will determine voltage
and life.
> Perhaps some kind of setup with pipes-inside-of-pipes.
> Pehaps you could then build the cells up inside of some lengths of PVC?
lot of work though, when you can just use scraps like food tins etc
> 4 inch diameter PVC,maybe 3-4 feet long,with a copper pipe inside of a
> steel pipe,inside of the PVC pipe?
holy ---, what are you going to power off this thing?
> Keep a bag of salt next to it,and when the power goes out,dump some salt
> and water in the cells,and turn on a (LED) light or something for a
> while.. could be handy.
whats needed is to scrape the electrode, not add salt. A steel bristled
brush works, but of course will corrode away rapidly itself.
> I recall seeing an "emergency battery" that used sea/salt water for an
> electrolyte..apparently it went through electrodes quickly..
> But it had a decent capacity,and was fairly small,maybe half the size of
> a car battery?
> But I've no idea what exactly they used for electrodes.
> It could be useful to have a "backup" battery with an infinite shelf
> life,untill you fill it.
exactly.
> Perhaps then you could just rinse it out,and store the electrolyte (or
> not,saltwater is fairly non-toxic,shouldn't be an issue to dispose
> of/dump.) and store it untill you need it again?
right, but bear in mind its not just salt water once its used. You'll
have FeCl in there as well, if you use steel.
> I'd actually like to build something like this,but at this point it's
> just a half-thought bouncing around my brain.
> If you have any ideas,I'd like to hear them!
These things work very well, but their one problem is very short
service life. And that renders them not the most useful IRL.
NT
phatty mo
> phatty mo wrote:
>
>
>>I've been wondering along similar lines..
>>I've been wondering how I could make a reasonable ~12V battery,cheaply
>>and easily.
>
>
> I've done just what you talk about, so can offer a few details on mine.
>
>
>>Maybe some saltwater cells,built up in Tupperware containers?
>
>
> Here you can buy flat multicompartment cases for £2, with 18 sections,
> used for storing screws etc. These are ideal as long as you can keep
> the thing horizontal while active. Tip it up and the water would run
> between cells.
>
>
>>Assuming maybe 0.5V per cell,and (if they're large enough) perhaps 10AH?
>
>
> I think people are underestimateing here. I used an M3 bolt and a bit
> of carbon, which will fit into a roughly 1" bottle cap, and got 1v 0.5A
> all day. Thats 5Ah or more. So a multicompartment tray would provide
> several times the Ah at 18v.
>
Wow,I had thought about those little multi-compartment boxes,but I
didn't think a "simple cell" that size would have any real juice to it..
I have a couple here i could play with.
500ma? really? Nice!
What did you use for electrodes and an electrolyte,just saltwater?
>
>>24 containers in series,it would be fairly large!
>>If we can find some good electrode materials,the cell voltage may go
>>up,so we would need less cells/containers
>
>
> Well... the more V you want out, the faster it corrodes. Mine gave very
> little out after 24hrs, but scraping the steel renewed it, so I'd go
> for long service life as far as poss. I reckon one could easily improve
> on steel as an electrode, but its free in large amounts.
>
>
>
>>Salt and water are both readily available,and pretty cheap,so the
>>electrolyte could be replenished easily enough...(any ideas for
>>something better,that's easy to get,and fairly cheap?)
>
>
> exactly
>
>
>>But,I'm not sure what would be best to use as "plates",keeping the
>>cheap,and easy concept in mind.(They will eventually corrode away,right?)
>
>
> yes, thats the nature of batteries. The lower the whatnot of the plate
> materials, the slower they corrode. So pick one plate as low as poss on
> your electrowhatever it is scale, and the other will determine voltage
> and life.
>
>
>
>>Perhaps some kind of setup with pipes-inside-of-pipes.
>>Pehaps you could then build the cells up inside of some lengths of PVC?
>
>
> lot of work though, when you can just use scraps like food tins etc
>
True,But see below..
>
>>4 inch diameter PVC,maybe 3-4 feet long,with a copper pipe inside of a
>>steel pipe,inside of the PVC pipe?
>
>
> holy ---, what are you going to power off this thing?
>
In short,as much as I can!
If the power goes out,and my main battery bank is drained,or i'm not
near it (away from home)it would be nice to have a 12V battery I could
run some lights,and a radio or something off of.A large capacity would
be a good thing.
10AH is just a starting point,if I could I'd like to build a (say)
50-100AH version. (the equiv of a car battery or two.)
Maybe run some CFL lights from an inverter in the house or something for
a day or two?
Perhaps the TV for a bit? My PC?
CB radio,scanner,cellphone charger,etc..?
>
>>Keep a bag of salt next to it,and when the power goes out,dump some salt
>>and water in the cells,and turn on a (LED) light or something for a
>>while.. could be handy.
>
>
> whats needed is to scrape the electrode, not add salt. A steel bristled
> brush works, but of course will corrode away rapidly itself.
>
Well,i was thinking of storing the battery "Dry" untill needed (and
possibly draining/rinsing it after use) that way the electrodes won't
dissolve away in the meantime..
So to use it,you'd pour saltwater (or other electrolyte) in there,and
connect a load.
Agitation is a good point though. I wonder if a small air pump would
help..maybe put a "bubble stone" for aquariums in the bottom of each
cell to help keep the electrolyte mixed,and help knock the 'crust' off
the plates?
>
>
>>I recall seeing an "emergency battery" that used sea/salt water for an
>>electrolyte..apparently it went through electrodes quickly..
>>But it had a decent capacity,and was fairly small,maybe half the size of
>>a car battery?
>>But I've no idea what exactly they used for electrodes.
>>It could be useful to have a "backup" battery with an infinite shelf
>>life,untill you fill it.
>
>
> exactly.
>
>
>>Perhaps then you could just rinse it out,and store the electrolyte (or
>>not,saltwater is fairly non-toxic,shouldn't be an issue to dispose
>>of/dump.) and store it untill you need it again?
>
>
> right, but bear in mind its not just salt water once its used. You'll
> have FeCl in there as well, if you use steel.
>
Ahh,yes..good point.
Actually,I wonder..if FeCl could be useful for etching printed circuit
boards. ;-) (I believe thats what is used as an etchant?)
>
>>I'd actually like to build something like this,but at this point it's
>>just a half-thought bouncing around my brain.
>>If you have any ideas,I'd like to hear them!
>
>
> These things work very well, but their one problem is very short
> service life. And that renders them not the most useful IRL.
Yea,that might be okay though.In an "emergency" situation,it might just
be enough to get by with for a night or two.
>
> NT
>
meow...@care2.com
> Wow,I had thought about those little multi-compartment boxes,but I
> didn't think a "simple cell" that size would have any real juice to it..
> I have a couple here i could play with.
Think what a dry cell that size can do.
> 500ma? really? Nice!
Yes I was surprised how powerful it was.
> What did you use for electrodes and an electrolyte,just saltwater?
salt water electrolyte, carbon and steel electrodes. The carbon doesnt
corrode, but the steel does, and rapidly.
> >>4 inch diameter PVC,maybe 3-4 feet long,with a copper pipe inside of a
> >>steel pipe,inside of the PVC pipe?
> >
> > holy ---, what are you going to power off this thing?
>
> In short,as much as I can!
Never mind AA and D cells, I can imagine people walking into shops, and
asking for Triple Z cells please.
What would it really produce?
Mine was 1" wide, 0.5" deep, and I made no attempt to get max electrode
area into there.
Yours is 4" wide, 48" long... so you've got 4^2 x 48/0.5 times the
voolume there. Thats 1526x as big. So you should get around 700A at 1v.
0.7kW per cell, so yes you really could heat the place on a set of
those.
Now design them properly so you get optimised electrode areas to
electrolyte capacity, and youre likely looking at 2 or 3 thousand amps.
Dont even think about shorting one of those!
> If the power goes out,and my main battery bank is drained,or i'm not
> near it (away from home)it would be nice to have a 12V battery I could
> run some lights,and a radio or something off of.A large capacity would
> be a good thing.
Ha, reckon youre a few orders of magnitude OTT there :)
> 10AH is just a starting point,if I could I'd like to build a (say)
> 50-100AH version. (the equiv of a car battery or two.)
Well yours would be what, say 1000A for 10 hrs... 10,000 Ah
> Maybe run some CFL lights from an inverter in the house or something for
> a day or two?
> Perhaps the TV for a bit? My PC?
> CB radio,scanner,cellphone charger,etc..?
Yours would more like light the town, power the local cinema, power the
university computing department, and the local radio transmitter.
> > whats needed is to scrape the electrode, not add salt. A steel bristled
> > brush works, but of course will corrode away rapidly itself.
>
> Well,i was thinking of storing the battery "Dry" untill needed (and
> possibly draining/rinsing it after use) that way the electrodes won't
> dissolve away in the meantime..
yes, thats necessary.
> So to use it,you'd pour saltwater (or other electrolyte) in there,and
> connect a load.
> Agitation is a good point though. I wonder if a small air pump would
> help..maybe put a "bubble stone" for aquariums in the bottom of each
> cell to help keep the electrolyte mixed,and help knock the 'crust' off
> the plates?
Well, I don know what you'll use, but with steel the crust was attached
pretty hard. An angle grinder would make more progress than an airstone
if youre using steel.
> > right, but bear in mind its not just salt water once its used. You'll
> > have FeCl in there as well, if you use steel.
>
> Ahh,yes..good point.
> Actually,I wonder..if FeCl could be useful for etching printed circuit
> boards. ;-) (I believe thats what is used as an etchant?)
yes, but it wont be anywhere near strong enough. Least mine wasnt after
1 day anyway.
NT
Evgenij Barsukov
Main thing is, where do you get the "active" component, the fuel - e.g.
anode material.
Cathode material can be carbon/oxigen, which is widely availabe on the
island assuming you can make fire and carbonize some branches.
The only known to humans (since more than 4 thousand years) method
of getting material suited as active anode is high-temperature reduction
of iron ores with carbon (same applies to Zn ores if you can find them).
This can be done in hand-made large ceramic
pots that are pre-heated with outside camp-fire (with a blower) with
subsequent placement of iron ore and carbon and closing the lead.
Rudimentary iron will be produced. It will be very corrosive because of
impurities, but that is exactly what we want. Purr iron on a flat stone
to make a semi-flat shape electrodes.
While iron electrodes are cooling, make wires out of Cu nuggets that are
found in nearby mountains by flattening them with a stone and cutting in
stripes.
Once done, connect iron plates to Cu wires as Anode,
and Cu wires to carbonized branches as cathode.
Further assembly provides easy access of oxigen to carbon:
1) wrap iron plate with a self-woven out of coconat fibers piece
of cloth
2) atach carbon cathodes to the outer side of the cloth, wrap
it again with loose coconut fibers.
3) immerce the contraption into salt-water by 1/3, so that both
cloth get wet, but oxigen access is still there.
Battery is ready. It is going to have Fe vs O2 potential (about 1V),
so place 12 of them in series to get 12V. Because we used large
surface area electrodes, it will give a noticeable current, while only
for a few days until iron is heavily passivated with corrosion.
After that, disassemble and clean the rust by strongly hitting the iron
electrodes with stone.
If current value is not enough for your radio, make ten of such
contraptions and place it in parallel. That is what Volta did for
his electricity demonstrations with his voltaic piles (in fact he
had about 200 placed in parallel!).
If you use the method of producing sulfuric acid by pyrolysis of FeSO4
ores, described in Misterious Island by Joule Verne:
http://www.nalanda.nitc.ac.in/resources/english/etext-project/julesverne/milnd10/index.htm
you can use sulfuric acid instead of salt water.
In this case you will be able to achieve realy high currents,
maybe even your satellite-phone would work! Buy me some beer once
you arrive home...
Regards,
Evgenij
daestrom
"Dave Plowman (News)" <da...@davenoise.co.uk> wrote in message
news:4de328d...@davenoise.co.uk...
> In article <Goednf0gfr8...@athenet.net>,
> philo <ph...@privacy.net> wrote:
>> a "Robinson Crusoe" battery must be one you'd make if stranded on an
>> island... so you'd have plenty of sea water. you could use electrodes of
>> copper and zinc
>
> Plenty of that on the average desert island...;-)
>
Well, if you were shipwrecked, you might pry the anti-corrosion zincs off
the hull, and along with the bronze/brass fittings, you might get some
potential.
Of course, once you've used up the zincs, I think you're pretty much done.
daestrom
Someone
With an emergency (assuming no electricity) you can forget about
"charging it". What you want to do is generate it in my opinion.
clareatsnyder.on.ca
wrote:
The carbon/iron/saltwater cell is a "primary" cell - and not
rechargeable.
Harry Chickpea
SolarFlare
"Harry Chickpea" <hchickpe...@hotmail.com> wrote
in message news:43bb28f8.467386@localhost...
BobG
canker eradication program... the state cut em all down). I wondered
about building 'citric acid' electrolye batteries as I picked up
garbage cans full of oranges and grapfruit.
SolarFlare
materials though?
Some batteries are just lemons when they first come
out.
"BobG" <bobga...@aol.com> wrote in message
news:1136343764....@g47g2000cwa.googlegroups.com...
Too_Many_Tools
The Professor would be proud. ;<)
How about a few comments from the hams amoung us...doesn't this qualify
as the ultimate Field Day challenge?
TMT
WA5OES
news:1136229191....@g49g2000cwa.googlegroups.com:
> Reading the thread on the Voltaic pile in
sci.chem.electrochem.battery,
> I started considering what would one have to do to build a "Robinson
> Crusoe" battery to power equipment in an emergency.
>
> Assuming a battery of 12v and respectable current to power
> communications equipment, how would you do it?
>
> What materials would you use?
>
> How would you charge it?
>
> I look forward to your contributions.
>
> TMT
>
What would Robinson need the battery for?
Too_Many_Tools
equipment.
It is assuming that Robinson Crusoe wants to be rescued.
The discussion has demonstrated to me how we tend to underestimate how
hard it is to provide basic needs to support our technology based life.
Maybe we should enlarge the scope of the problem and allow active power
generation.
Any ideas as to how to generate power?
TMT
mcal...@ksu.edu
>....[snip]....
>Maybe we should enlarge the scope of the problem and allow active power
>generation.
>Any ideas as to how to generate power?
The problem needs better definition. May we assume Robinson has been
able to recover large rolls of wire, etc., from his ship, or does he
have to mine the ore, smelt it, make the appropriate dies, pull the
wire, ................. (lotsa dots!), or may we assume he has EVERYTHING
EXCEPT a generator (i.e., his island once held a thriving modern-type
civilization but all of its generators have rusted?
--
--Myron A. Calhoun.
Five boxes preserve our freedoms: soap, ballot, witness, jury, and cartridge
PhD EE (retired). "Barbershop" tenor. CDL(PTXS). W0PBV. (785) 539-4448
NRA Life Member and Certified Instructor (Home Firearm Safety, Rifle, Pistol)
Too_Many_Tools
in detail. The object of the discussion is to facillate discussion
about what a survivor would have to consider, need and build to get
power to operate the comm set and hopefully initiate rescue operations.
If one consider poor Crusoe's plight, he is stranded on an island that
he doesn't know what is available...he has to find and use what is
available. I was hoping the group would speculate on what he might have
available. Part of the intent is to consider what the minimum would be
needed to pull this off.
I did mention that he had comm gear that would use a 12 volt
battery....so I am assuming that parts of his boat/plane washed up on
the shore of the island. The battery could just as well power a island
built spark generator, a light bulb for night signaling, ignite fires
or homemade explosives....again, remember this poor guy is trying to
attract attention to his plight.
How about some more wild ideas...Crusoe is getting sick of eating
coconuts. ;<)
TMT
jakdedert
>>....[snip]....
>>Maybe we should enlarge the scope of the problem and allow active power
>>generation.
>>Any ideas as to how to generate power?
>
>
> The problem needs better definition. May we assume Robinson has been
> able to recover large rolls of wire, etc., from his ship, or does he
> have to mine the ore, smelt it, make the appropriate dies, pull the
> wire, ................. (lotsa dots!), or may we assume he has EVERYTHING
> EXCEPT a generator (i.e., his island once held a thriving modern-type
> civilization but all of its generators have rusted?
Robinson 'could'--with nothing more than the battery and some
wire--transmit radio signals in Morse....
No accounting for range, of course.
jak
Harry Chickpea
>How about some more wild ideas...Crusoe is getting sick of eating
>coconuts. ;<)
Electric eels.
phatty mo
Look around,You might find some "litter" for the cells..old tin
cans,rods,bars,nuts+bolts,fish hooks,whatever.. Maybe you'd get lucky
and find a wrecked(,or parts of a) boat or plane,or get really lucky and
find parts from the boat/planes electrical gizmos to play with.
Maybe wire up some lights,or a simple (spark gap) transmitter,and send
out an SOS.Dunno if anyone would see the lights,or what you'd use for an
antenna...anything you can find,I guess.
Or just touch the eels together,Spark-gap and arc-light all on one!
void * clvrmnky()
You've certainly proved your mettle with that one.
Too_Many_Tools
wire--transmit radio signals in Morse....
No accounting for range, of course.
jak "
True...but this just shows how important the battery really is...and
that is why I chose to make it the main focus of Crusoe's efforts to
get attention.
TMT
SJC
"Too_Many_Tools" <too_man...@yahoo.com> wrote in message news:1136570313.3...@g44g2000cwa.googlegroups.com...
It seems that if he is really into renewable and sustainable,
he does not have to be rescued at all.
H. P. Friedrichs
didn't involve the use of any batteries at all. The transmitter was a
length of wire cut to 1/4 wavelength and suspended by a tree or a kite.
The feed end was linked to ground through a key.
An antenna of any length is likely to accumulate a charge from
electrostatic field present in the atmosphere...200 volts/meter if I
remember correctly. Keying that charge to ground produces oscillations
that supposedly could be picked up many miles away....probably even
farther now with modern receivers.
Pete
AC7ZL
Ken Scharf
> Reading the thread on the Voltaic pile in sci.chem.electrochem.battery,
> I started considering what would one have to do to build a "Robinson
> Crusoe" battery to power equipment in an emergency.
>
> Assuming a battery of 12v and respectable current to power
> communications equipment, how would you do it?
>
> What materials would you use?
>
> How would you charge it?
>
> I look forward to your contributions.
>
> TMT
>
found in Bhagdad. It had an iron rod negative pole and a copper
cylinder positive pole, and probably used vinegar as the electrolyte.
A clay jar housed the unit. What would a battery be used for 2000
years ago? BION, electroplating gold!
JoeSP
<meow...@care2.com> wrote in message
news:1136248266.7...@o13g2000cwo.googlegroups.com...
> Dave Plowman (News) wrote:
>> In article <Goednf0gfr8...@athenet.net>,
>> philo <ph...@privacy.net> wrote:
>> > a "Robinson Crusoe" battery must be one you'd make if stranded on an
>> > island... so you'd have plenty of sea water. you could use electrodes
>> > of
>> > copper and zinc
>>
>> Plenty of that on the average desert island...;-)
>
> and carbon and steel electrodes. Assuming there is no ready metal on
> the island, hopefully there would be a zip on some clothing, a button
> or something. Burnt vegetation could provide the carbon.
>
> I found a little 1" or so bottletop sized cell gave in the region of
> half an amp at 1v. The electrodes corrode quickly, in a day.
What's the point? You can make a battery out of many, many substances, but
only a few of them are economical, practical or useful.
clifto
> Robinson 'could'--with nothing more than the battery and some
> wire--transmit radio signals in Morse....
Yeah, but all the people who understand Morse would be too old to be
traveling around deserted islands.
--
If John McCain gets the 2008 Republican Presidential nomination,
my vote for President will be a write-in for Jiang Zemin.
Andrew VK3BFA
Too_Many_Tools wrote:
> Reading the thread on the Voltaic pile in sci.chem.electrochem.battery,
> I started considering what would one have to do to build a "Robinson
> Crusoe" battery to power equipment in an emergency.
>
> Assuming a battery of 12v and respectable current to power
> communications equipment, how would you do it?
>
> What materials would you use?
>
> How would you charge it?
>
> I look forward to your contributions.
>
> TMT
Nah, its easy. Find the crashed WW2 B24 in the jungle. Pull out all the
radio gear (it would have been "tropic proofed" and so would work -
anyway, it was better quality than todays modern plastic junk) - pull a
28 volt generator off one of the engines, and with your Swiss Army
Knife carve a propellor to fit it (the original props were wrecked
when it crashed) - then, wait for the next windy day, and hit the TX
switch. Easy as......
73 de VK3BFA Andrew.
JoeSP
Much cheaper sources of better electrolytes exist. Using free scraps and
substances will produce a theoretical battery much sooner than a practical
one.
I sense that this discussion is being propelled by the desire to get
something for nothing or very cheap. If you do your homework, you may be
able to match the materials available to the desired output, and get
something safe and practical, but I doubt it. I'd be as interested as
anyone to see the results if you're successful.
JoeSP
Why do you think it was mostly dry cells and dynamos a century ago? Don't
you think they experimented with every metal and electrolyte available
before coming up with the lead-acid battery and the dry cell? If you're
keen to repeat history, have fun.
JoeSP
If the professor couldn't build a crude radio transmitter with all the other
advanced technology he managed to build, he wasn't a very good professor.
JoeSP
"Ken Scharf" <wa2mze...@bellsouth.net> wrote in message
news:Rhdwf.20965$0y2....@bignews2.bellsouth.net...
It was probably used by Hammurabi to play jokes on his friends by
electrifying the chairs.
John Savage
>in an emergency, For materials, I would use a brick to smash Radio
>Shack's window and get all the batteries I need.
All the batteries? Then you'd better do that before Friday!
>> What materials would you use?
To fabricate a cell with dissimilar metals + salt water electrolyte you
simply search in the sand for different bags of dubloons--and hope they
came from batches of alloy sufficiently dissimilar to generate a worth-
while potential difference. If not, then jump the next pirate who comes
ashore and steal his sword: it's iron or steel. Use that as one of the
electrode metals for your battery. But you can't escape the island in
the pirate's rowboat, that would be against the spirit of adventure ....
--
John Savage (my news address is not valid for email)