Camping Generator

[[email protected]]

I'd like to recharge my cell phones and maybe even laptop when camping.

I've played with solar cels, but they did little, especially on cloudy
days.

Is is reasonable to imagine that I could set up a steam engine to run a
small electric generator, with the power coming from a pressure cooker set
next to the campfire?

I've not yet been successful in determining the output power from model
steam engines, nor in finding out how much power would be needed to turn a
small 12 volt motor or other 12 volt electrical generator.

Anybody got any advice or experience?

Should I just carry a small charged-up 12 volt sealed vehicle battery with
me and forget about the fun of using a steam engine?

 

[vaughn]

Is is reasonable to imagine that I could set up a steam engine to run a
small electric generator, with the power coming from a pressure cooker set
next to the campfire?

This same (or remarkably similar) question has been asked before, and the
answer is still no. Steam can be fun, but play with it at home, not out in
the boonies. Your precharged battery is a good idea, or invest in a small
gasoline generator to charge the battery as necessary.

Vaughn

 

[nunya]

[email protected] wrote in

I'd like to recharge my cell phones and maybe even laptop when
camping.

I've played with solar cels, but they did little, especially on cloudy
days.

Is is reasonable to imagine that I could set up a steam engine to run
a small electric generator, with the power coming from a pressure
cooker set next to the campfire?

I've not yet been successful in determining the output power from
model steam engines, nor in finding out how much power would be needed
to turn a small 12 volt motor or other 12 volt electrical generator.

Anybody got any advice or experience?

Should I just carry a small charged-up 12 volt sealed vehicle battery
with me and forget about the fun of using a steam engine?

http://www.stationroadsteam.com/archive/1632.htm
http://www.radarreturns.net.au/assets/issues/RR Vol3 No4.pdf

The device you mention has already been invented for use in WWII
I am very interested but have nor been able to come up with any plans or
blueprints, it would be a fun construction project.
Scott

 

[andrew]

Forget the hazards and complexity of steam and look at a thermopile
generator. These can be found in the little heat powered fans that you
put on top of a wood stove. You can expand on the basic design to
generate more power.

Yes I think this is a good route, it will probably challenge the conversion
efficency of the SOE firefly set too.

These small fans tend to use the peltier devices found in small 12V fridges.
You must be careful not to heat them over 150C, at least one of the
stovetop fans, the ecofan, uses a bimetal strip to decouple the peltier
from the hot source. These things are very low output. The one I took from
a refrigerator barely produced 2V at a delta T of ~120C but I didn't
measure the current draw of the little motor.

I guess one could fabricate 4 or 8 of them in an ally tube which could sit
on a kelly kettle flue and nest inside it for transport.

AJH

 

[Malcolm \Mal\ Reynolds]

I'd like to recharge my cell phones and maybe even laptop when camping.

I've played with solar cels, but they did little, especially on cloudy
days.

Is is reasonable to imagine that I could set up a steam engine to run a
small electric generator, with the power coming from a pressure cooker set
next to the campfire?

I've not yet been successful in determining the output power from model
steam engines, nor in finding out how much power would be needed to turn a
small 12 volt motor or other 12 volt electrical generator.

Anybody got any advice or experience?

Should I just carry a small charged-up 12 volt sealed vehicle battery with
me and forget about the fun of using a steam engine?

Camping with a laptop isn't camping.

 

[Winston]

How about those Honeywell thermopiles that sit in the pilot light and
produce .75v to hold the gas valveopen? I forget their output
impedance... I think it was 50ohms... but a couple of germainium
transistors wired as a multvibrator could run from the .75v, run the
square wave out thru a couple of inductors, catch the spikes with a
couple of shottky diodes and a BFC and you're ready to charge.

Sounds like a Joule Thief:
http://www.instructables.com/id/SBXFBQFFOHU388P/

--Winston

 

[Malcolm \Mal\ Reynolds]

Sure it is. Not everyone camping is interesting in old time "roughing
it", some folks go on camping trips for such reasons as nature
photography, and in this age of DSLRs, reviewing the days shots on the
laptop by the campfire while dinner is cooking is perfectly normal
"camping".

In this age of DSLRs, memory is cheap and abundant and you can review the
shots on the viewfinder of any DSLR. If you want to do photo studio work,
don't call it camping.

 

[Scott]

Sure it is. Not everyone camping is interesting in old time "roughing
it", some folks go on camping trips for such reasons as nature
photography, and in this age of DSLRs, reviewing the days shots on the
laptop by the campfire while dinner is cooking is perfectly normal
"camping".

"If you bring along a vacuum cleaner, it isn't camping."

We have an RV we use for boondocking, which is somewhere between real
camping and having a very small house with a permanent power outage. We
have 150AH of battery, a 3.4kW generator, and a 130W solar panel. We bring
a laptop and a couple of cell phones, in addition to the RV's general power
loads. We're still learning how to get the most out of what we have, but in
mild weather we can go 4-5 days on the battery alone.

To the OP, I have only two recommendations. First, for short trips or
modest power needs, lug along a small deep-cycle battery in the 70-80AH
range. That will give you probably 6-8 hours of laptop run time, more if
you don't watch DVDs and keep the screen dim.

Cell phones don't use much power. I'd estimate 0.4AH/day for standby, and
maybe (?) 0.4AH per hour of talk time. Do the math based on your usage
patterns.

However -- and this is important -- make sure you have 12VDC adapters for
your gear. Powering AC-DC adapters with an inverter can be remarkably
inefficient. I started out using my laptop's AC adapter with a Belkin
inverter. When I located a DC-DC adapter, I found that it drew
significantly less current than the inverter plus AC adapter. Well worth
the modest price.

Second, for longer trips or greater power needs, bring a small generator.
There's a little 1kW Chinese-made jobbie that's been under recent discussion
here. Although it's no longer on sale for $99, at its regular $150 price it
still looks like a pretty sweet deal to me.

In no case would I recommend fiddling about with steam or Peltier devices.
Too much hassle, too much to go wrong. Maybe with enough space and time to
set up and fine-tune a steam rig, then *maybe*, but for a weekend jaunt in
the hills, no way.

 

[andrew]

I was composing a reply last night when a transient power outage hit, oddly
enough my battery free 12V PC stayed up but this one went down and lost
data, it's such a rare occurrence here I don't use a UPS. It got me
thinking though with PCs using 5V and 12V why do we not use the battery
voltage directly at the outlet of the psu rather than invert it to mains
voltage and frequency?

Anyway when I looked at these Honewell thermopiles they were for furnaces
with no mains available so they power the gas valve directly from Voltage
produced, they also cost about USD45.

Philipps make a stove for sale in India with a semiconductor TEG that can
withstand 400C. Caterpillar are using some to generate all electric power
for a truck from its exhaust. The appeal of using these little Peltier
effect devices is that mass production is making them cheap, they're used
in 12V beer coolers (which get discarded here once people realise they
flatten the car battery in less than a day) and now in some cpu cooling for
PCs, I see 150W ones for <USD9, mind that's their consumption, I guess
you'd be lucky to get 1W at 2V out of one.

Sounds like a Joule Thief:
http://www.instructables.com/id/SBXFBQFFOHU388P/

Yes I was thinking of that, a friend working on a project to self power a
cooking stove fan reckons he wants about 1V to charge 3 AA cells and run a
PWM voltage control for the fan. The idea is to co produce enough current
to power a reading light also. With 3 bright leds in a case with battery
holder for 3 AAAs at less than USD1 it's all beginning to look affordable
for people with no electricity.

AJH

 

[Neon John]

Philipps make a stove for sale in India with a semiconductor TEG that can
withstand 400C. Caterpillar are using some to generate all electric power
for a truck from its exhaust. The appeal of using these little Peltier
effect devices is that mass production is making them cheap, they're used
in 12V beer coolers (which get discarded here once people realise they
flatten the car battery in less than a day) and now in some cpu cooling for
PCs, I see 150W ones for <USD9, mind that's their consumption, I guess
you'd be lucky to get 1W at 2V out of one.

Do you have any pointers to e-stores which might be selling the high
temperature piles (Seebeck instead of Peltier when generating.)? I'd love to
get my hands on some, even if they have to be shipped from India.

Several years ago I made an emergency battery charger for my RV using ordinary
Peltier piles (surplus) and a propane torch burner. It works well, generating
something like 5 amps at 14 volts but I have to be very careful about
overheating. I'd love to get some high temperature ones.

John
--
John De Armond
See my website for my current email address
http://www.neon-john.com
http://www.johndearmond.com <-- best little blog on the net!
Tellico Plains, Occupied TN
What do you call a blonde's cranial cavity? Vacuum chamber?

 

[[email protected]]

The device you mention has already been invented for use in WWII

WOW! Yes, that is what I am looking to buy/build/play with!

I saved it as an eBay search. If one comes up I'll get an email.

 

[[email protected]]

How about those Honeywell thermopiles that sit in the pilot light and
produce .75v to hold the gas valveopen? I forget their output
impedance... I think it was 50ohms... but a couple of germainium
transistors wired as a multvibrator could run from the .75v, run the
square wave out thru a couple of inductors, catch the spikes with a
couple of shottky diodes and a BFC and you're ready to charge.

I'm not familiar with those. I've looked briefly into thermopiles, but I
didn't get very far, because steam engines caught my attention.

A thermopile would be great. Originally, I was thinking along the lines
of a black box that I could bury in the coals and have electricity come
out. A thermopile is that sort of a device.

 

[[email protected]]

Sounds like a Joule Thief:
http://www.instructables.com/id/SBXFBQFFOHU388P/

The joule thief idea is very cool. THere's always lots of semi-dead
batteries while camping. They could be used to keep the cellphones
charged.

That way, once the flashlight starts to dim a little, you could put
in fresh batteries and not feel bad about wasting the little bit of power
left in the old batteries. The old ones can be sucked dry to recharge the
cellphones.

 

[[email protected]]

Camping with a laptop isn't camping.

It is if you are on a small island with no electricity or running water.

 

[[email protected]]

To the OP, I have only two recommendations. First, for short trips or
modest power needs, lug along a small deep-cycle battery in the 70-80AH
range. That will give you probably 6-8 hours of laptop run time, more if
you don't watch DVDs and keep the screen dim.

I generally go for two weeks to an island which has no electricity.
Things are brought over on a boat, so weight is not the biggest factor,
but it is a factor.

Cell phones don't use much power. I'd estimate 0.4AH/day for standby, and
maybe (?) 0.4AH per hour of talk time. Do the math based on your usage
patterns.

THey go dead after a few days.

However -- and this is important -- make sure you have 12VDC adapters for
your gear.

Yep. I was thinking of standardizing on 12v, since just about everything
has provision for plugging into a car jack.

Second, for longer trips or greater power needs, bring a small generator.
There's a little 1kW Chinese-made jobbie that's been under recent discussion
here. Although it's no longer on sale for $99, at its regular $150 price it
still looks like a pretty sweet deal to me.

I'll look into it, but that sounds like less fun. I want to turn my
campfire into electricity! Every night we produce HUGE amounts of energy
burning wood. My thinking is that there's got to be a good way to capture
some of it and convert it into electricty.

In no case would I recommend fiddling about with steam or Peltier devices.
Too much hassle, too much to go wrong. Maybe with enough space and time to
set up and fine-tune a steam rig, then *maybe*, but for a weekend jaunt in
the hills, no way.

How about two weeks on an island?

 

[Bruce in alaska]

I'm not familiar with those. I've looked briefly into thermopiles, but I
didn't get very far, because steam engines caught my attention.

A thermopile would be great. Originally, I was thinking along the lines
of a black box that I could bury in the coals and have electricity come
out. A thermopile is that sort of a device.

ThermoElectric Generation (Peltier Junction) REQUIRES not only a HOT Side
but ALSO a COLD Side, and generates power on the difference in
temperature between the two. I have a Commercial Unit that is Propane
Fired, and produces 240 Watts using 1 USG/day. It uses ambient Air on
the Cold Side, and a BIG Heatsink to keep the Cold Side, cool. They are
not very efficient, or cheap, but they have NO MOVING PARTS, and don't
wear out.

 

[andrew]

They used to use a folding bicycle-type generator that put out all the
voltages needed for a field radio.

One of my mates was in signals and he said it was B hard work. Another
friend runs a field cinema using a bicycle with the rear wheel held off the
deck with a frame. This then drives the friction wheel from a 24V scooter
which is smoothed by 2 1 farad capacitors and runs the show, I've never
pedalled it in earnest but 50W seems about sustainable for a few hours.

AJH

 

[andrew]

Do you have any pointers to e-stores which might be selling the high
temperature piles

Sorry I don't.

That's why the little Peltier devices appeal, they're more readily
available, if you can think of a way of preventing overheat.

The stoves case is a good one because there's a steady source of cooling
air, because it's needed for combustion.

AJH

 

[Malcolm \Mal\ Reynolds]

You can only review framing in the feeble little LCD on the camera, if
you want to assess the images in more detail so you can make adjustments
on the next days shots you need a larger and better display.

That's why good photographers "bracket"

Also, you need to lookup the definition of camping.

You aren't describing camping, you are describing a photo shoot...totally
different things

 

[Neon John]

I'm not familiar with those. I've looked briefly into thermopiles, but I
didn't get very far, because steam engines caught my attention.

A thermopile would be great. Originally, I was thinking along the lines
of a black box that I could bury in the coals and have electricity come
out. A thermopile is that sort of a device.

A thermopile puts out 750 mv at a few hundred MA. It looks like a regular
safety thermocouple on steroids, perhaps 3/8" diameter and about an inch long.
Inside are many thermocouples in series, each generating just a few mv.

That is enough power to operate the coil in a combination gas valve designed
for the application and to push the current through a reasonable length of
thermostat wire to an external thermostat.

IN use, the hot end need to be at least a dull red and the cold end needs to
be at near room temperature. The latter will be your biggest problem, keeping
the cold end cool. Google for "Honeywell Thermopile Generator" and you'll get
a lot of info. About the third or 4th hit is a spec sheet of sorts from
Honeywell.

John
--
John De Armond
See my website for my current email address
http://www.neon-john.com
http://www.johndearmond.com <-- best little blog on the net!
Tellico Plains, Occupied TN
What do you call a blonde's cranial cavity? Vacuum chamber?