Introduction: Battery Powered Hand Warmer

This is my first instructable so be kind. I wanted to make a hand warmer that was battery powered and rechargeable. I welcome any and all criticism. If you have any questions please feel free to ask.

Step 1: Parts List

Tools & Parts

  • Heat resistant tape
  • Hot glue gun
  • knife
  • Soldering iron
  • Balsa wood
  • 28 awg wire (about three feet)
  • Switch
  • AA battery holder
  • Cover cloth
  • AA batteries

Step 2: Prep Work

  1. Start by outlining the battery holder on the balsa wood with a pencil. You will want to leave about 1/2 inch extra on the length to make room for the switch.
  2. Cut the stenciled rectangle out with a knife.
  3. Take 3 ft. of wire (I used 28 gauge copper bead wire) and wrap it around the wood (be sure to keep the wires from touching as you spiral it across the balsa).
  4. Tape the ends of the wire with a heat resistant tape to the wood.

Step 3: Install and Drive On!

  • After finding a suitable place for the copper wire heating source. You will need to cut an appropriate slot for the switch.
  • After prepping the switch, glue in place with either hot glue or "CA".

Step 4: Glue and Solder

  • Solder all connections in place and prep for the cloth cover. (heat resistant tape is amazing at this stage)!!!

Step 5: Finish With Hot Glue

  • Hot glue the cloth to cover the heating coils.
  • Make sure to wrap fully around the heating coils(Don't worry, the coils should not produce enough heat to cause harm... theoretically around 100 -140 degrees Fahrenheit)
  • After the cloth is secure, hot glue the heating aspect to the battery holder.
  • It should last between 1 and 2 hrs.
  • Enjoy the warmth during the winter!!!!!!

(Disclaimer: Ensure to properly check connections and aggregate temperature).

Comments

author
Faizshaikh (author)2014-10-12

Winter Is coming :D ! Good job !

author
kode1303 (author)2014-10-11

Cool project! Have you calculated the wattage? (Volts * amperes = watts).
Considered using kanthal wire ("heat wire")? It has unusually high resistance, sp it's good for turning current into heat :-)

author
shounaki (author)kode13032014-10-12

I didn't think about that at the time. But that's definitely an idea I will look into.

author
Tad Rosenberg (author)2014-10-11

This is great! Thanks for sharing. Shine the light that you have

author
shounaki (author)Tad Rosenberg2014-10-11

Thank You!!!!

author
bratan (author)2014-10-20

Nice instructable. Two questions. Why balsa wood and specifically which heat resistant tape you used?

author
shounaki (author)bratan2014-10-20

I used balsa because it was extra left over and light. The tape was also left over, but I purchased it at harbor freight a while back. You could probably use duck tape and be fine, but heat resistant tape should be farely easy to spot at home depot or lowes.

author
fm00078. (author)shounaki2017-01-05

I did this decades ago... do not use Duct Tape.

It not only does it melt, it becomes GOOEY. A real sticky mess if it's not covered well.

.

author
ashaw19 (author)2015-09-13

is it possible to charge a mobile using hand warmer

author
BenjaminB10 (author)ashaw192016-11-19

why would you want to do that?

author
aespinal1986 (author)2014-10-20

Great idea! I ride my motorcycle year-round and with winter around the corner this might come in handy, I'd need a flexible material were I can slip under my gloves and be able to grip the handles.

author
Nmoleo­ (author)aespinal19862016-09-17

Not to be negative, but the batteries could melt because this is essentially a short circuit. Be careful!

author
coggs (author)aespinal19862014-10-20

Yeah, I'd like to be able to use it while snowboarding. I'm going to buy a cheap pair of thin glove liners and stitching the wire to the outside of it. Might even be possible to run the wire around the fingers as well! I'll probably attach some velcro to the battery pack and strap it around my wrist, running insulated wire to the gloves.

If it works I'll definitely be buying some rechargeable batteries for them!

author
shounaki (author)coggs2014-10-21

definitely, let me know how it turns out!

author
juanri2663 (author)2014-10-13

2 Questions:

1)Do you think its possible/safe to combine this design with clothes, for example, linen gloves?

2) Have you tried increasing the size of this project? (Higher voltage, extended wire, bigger wood, more battery power, etc)

Great project btw. Very clear and useful. Thanks!

author
shounaki (author)juanri26632014-10-13

Wow that's a great idea! It could totally work in a pair of gloves or even a shirt. It would take some work to sew it into the fabric. I did try to use a 6v battery but it burned the wire up. It was an enlightening experience.

author
Nmoleo­ (author)shounaki2016-09-17

Not to be negative, but the batteries could melt because this is essentially a short circuit. Be careful!

author
Nmoleo­ (author)2016-09-17

Very nice Instructable! However, the wire has so little resistance that it is basically shorting out the battery, and that could cause it to catch fire or leak acid.

author
LarissaP5 (author)2016-08-02

if I use silicone instead of the wood, work?

author
1 SEC2 (author)2016-07-26

How does it work?

author
fourfingers (author)2016-02-18

made it didn't think it was very warm until I Inadvertently left it switched on in my golf bag. When I got home the battery's had got so hot they melted the battery holder, and their outer casing's.

author
LarsB3 (author)2015-09-06

It is a very nice and working project, but you shorted the batteries.

author
chunzhen (author)2014-12-10

I come from Chinese, I have this idea, but I think there's a heating sheet low price comparison is just one yuan is low and low voltage can be convenient to use mobile power supply

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gogoguy (author)2014-10-13

nice instructable! pretty handy!

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unordinarypunk (author)2014-10-13

This is an awesome idea! I plan on building it, but I'm wondering, why Balsa wood specifically? Would other woods work as well?