Genius needed please :O)

Hello you lovely people

I have a problem i would like some help overcoming

I want to build a tiny heater that i can hang the batteries outside the boots and slip the heating element inside my boots and need suggestions or help in doing so, any suggestions would be gratefully received!

Ideally i would like to run the heater on a few AA/9v/Lithium batteries and make them for as cheap as is humanly possible

So far i am considering butchering a heated eyelash curler

Anyone know of any small (5p or 10p sized) things that will generate heat when a voltage of between 3v and 9v is passed through it

Must also be able to be waterproofed or ncased in a tiny housing that is waterproof

Please help me before my toes drop off from frostbite while nightfishing

Any clever ideas guys?

Thanks in advance for any help you can give

:O)

Basically all heaters are is resistors - but you are severely crippled by the lack of power available from small batteries. You essentially have the choice of a couple of minutes of warmth, or a longer period of not enough warmth to notice.

Get some better insulated boots.

Nigel Goodwin said:

Basically all heaters are is resistors - but you are severely crippled by the lack of power available from small batteries. You essentially have the choice of a couple of minutes of warmth, or a longer period of not enough warmth to notice.

Get some better insulated boots.

Click to expand...

Hi Nigel, thanks for your response

i only need a tiny amount of heat for short bursts of time, my boots are GREAT at keeping heat in, but they can only keep in the heat that is there

I have been walking/running in them when my toes are really feeling it but this has the drawback of sometimes making them sweaty

Can you think of a small flexible/flat resistor that would give off heat at between 3v and 12v?

thanks

Please help me before my toes drop off from frostbite while nightfishing

Click to expand...

Nothing will beat a quality pair of boots (as Nigel suggest) and some good socks. The problem with making heat from electricity is the heat you make is short lived. Batteries run down quickly.

Years ago I did my share of hunting and fishing (and freezing) but given a choice I opted for a chemical solution similar to this rather than an electric solution. I have no clue where you are but just about all sporting goods outlets carry them and they work well. I have used them for 6 to 8 hours and never got cold. The pocket hand warmers are also great.

Ron

Probably best to make you own using resistance wire - but I still doubt there's enough energy available to do much good.

Get 3 ohms worth of resistance wire (the actual length will depend on the type of wire).

Then connect it across your 3V batteries - see how warm it gets, and how long the batteries last (place a voltmeter across the batteries and see how the voltage falls).

This is producing 3W of heat - which is a pretty feeble amount.

Reloadron said:

Nothing will beat a quality pair of boots (as Nigel suggest) and some good socks. The problem with making heat from electricity is the heat you make is short lived. Batteries run down quickly.

Years ago I did my share of hunting and fishing (and freezing) but given a choice I opted for a chemical solution similar to this rather than an electric solution. I have no clue where you are but just about all sporting goods outlets carry them and they work well. I have used them for 6 to 8 hours and never got cold. The pocket hand warmers are also great.

Ron

Click to expand...

hi reloadron

they look good mate, but at $8 for one night i cant afford that! lol

i have a couple of the zippo style handwarmers and they work great, my hands are lovely and warm, infact every part of me is lovely and warm except the very ends of my toes

Ive got great 4 season boots and merino wool liner socks and heavy wool 4 season oversocks and when im moving around im never cold but my real problem is prolonged periods of inactivity lol like when im sleeping and then wake up thinking i have lost my feet

i know if i get my circulation going the blood will heat up my toes but when i go for a jog my feet can sometimes get sweaty and this makes things worse

these guys have done some rechargeable heated boots > Columbia Bugathermo hiking boots are heated, rechargeable -- Engadget but at $250 i was sure with some help i could do my own version a bit cheaper

there are battery powered insoles and socks aswell but they all suffer from easily being broken so i want to make something myself that is fairly bombproof

i bought my new boots about 3 sizes too big on purpose so i could fit a little something down the toe end for this reason

im sure we can think of something cant we guys!?

otherwise im ordering two eyelash curlers from china for £1 each and butchering them lol

Nigel Goodwin said:

Probably best to make you own using resistance wire - but I still doubt there's enough energy available to do much good.

Get 3 ohms worth of resistance wire (the actual length will depend on the type of wire).

Then connect it across your 3V batteries - see how warm it gets, and how long the batteries last (place a voltmeter across the batteries and see how the voltage falls).

This is producing 3W of heat - which is a pretty feeble amount.

Click to expand...

thanks for the tip nigel

im thinking of a 3 x AA battery pack or a 9v to power them so will factor that in, ive got so many rechargeables i think i better use them lol

i dont need a great amount of heat guys, just enough to stop my toes dropping off, when the temperature is -5 degrees C ... even 10degrees C will seem WARM and TOASTY to me

laptop batteries may do the job for you, if you can stop the heat from escaping then probably a small amount of energy may be needed to maintain the same temperature. Your toes could get sweaty though. You could wear a thin cotton socks first (for absorbing sweat) and then the heavier socks to retain the heat. You could also apply talcum powder to your feet before wearing socks, in India this is usually done (but not on the feet).

Be careful if you opt for any type of lithium ion batteries, though. They have a tendency to explode if shorted (learned from experience ).
Personally, I would go with Ron's idea. I have used that kind of foot warmer before and they do a great job.
Der Strom

I recently saw a discussion that ended with, "use the flat heater wire out of a toaster for resistance wire". Got any dead toasters?

Why not buy some heated socks?

#12 said:

I recently saw a discussion that ended with, "use the flat heater wire out of a toaster for resistance wire". Got any dead toasters?

Click to expand...

Just don't catch the boots on fire!

I hope his toes will notify him before the socks burst into flame!

I tried those electric socks before I went the chemical pad route. Never liked the things. They were never that warm and the batteries sucked.

Ron

Don't wear cotton socks, they absorb the moisture. Wear woolen socks and your feet won't feel sweaty.
Also, -5C is nothing. Try skiing in -30C for 4 hours at a time!

thanks for all the creative ideas guys! i looked at the heated socks and insoles but apparently they dont work v well and are v easily broken and my stuff gets put through the mill so i want something solid so i have to build it myself!

i think i've possibly had a eureka moment this evening while watching rambo 3 lol!

but obviously i need to run it by you genius's first because when it comes to ohms watts volts ac/dc etc i am but a mere baby so pick this idea apart please


i want to chop up a couple of those 5v 2.5w USB gimmicky coffee warmer things, they must have heating elements in them right? they have a nice long sturdy USB cord for me to plug into a 4 x AA switch box too, so ...

am i right in thinking that 4 x rechargeable AA = 4.8v

am i right in thinking those AA's will deliver DC current?

how long will 4 x 2500mah AA's last powering something that draws 5volts at 2.5watts please?

and am i right in thinking that hooking up the heating elements to a switch box will work? what else do i need to know?

thanks also for the tips on not using li-ion i dont want blown up feet!

please feel free to critiscise and mock me i realise i am only an ideas person and i need lots of help with them!

thanks again you guys are great!

edited* see post above please

4 hours....

#12 said:

4 hours....

Click to expand...

thank you very much sir!

that is plenty as i will only have them on for bursts of 5 minutes at a time!

right im gonna order the bits and see if i can codge something together, any tips on building it guys?

Don't hold the wire down with your finger while you're soldering it.