This neoprene battery case can hold two AA batteries or a 9Volt battery. It does take some time and patience to make this little pouch, but you then have a durable 3 or 9Volt power supply that can be used in various textile projects. Next step would be to include a 5Volt regulating circuit for the AA battery option.

The hooks and loops for connecting to the circuit, as shown in this Instructable, could be replaced by other conductive fasteners such as metal snaps, conductive Velcro, crocodile clips or even sewing a permanent connection with conductive thread.

I am also selling these handmade neoprene Battery Pouches via Etsy. Although it is much cheaper to make your own, purchasing one will help me support my prototyping and development costs >>
http://www.etsy.com/shop.php?user_id=5178109

Step 1: Materials and Tools

MATERIALS:
- Stretch conductive fabric from www.lessemf.com
(also see http://cnmat.berkeley.edu/resource/stretch_conductive_fabric
- Conductive thread from www.sparkfun.com
also see http://cnmat.berkeley.edu/resource/conductive_thread
- Fusible interfacing from local fabric store or
(also see www.shoppellon.com)
- 1.5 mm thick neoprene from www.sedochemicals.com
- Regular thread
- Set of 2 metal hooks and loops
- Pen and paper
- T-shirt transfer and permanent marker

TOOLS:
- Sewing needle
- Scissors
- Iron

Step 2: Cutting and Fusing

Print out or re-create the following stencil (see pictures). Then trace the stencil onto the neoprene and cut out along the outline.

Download JPG from >>
http://farm4.static.flickr.com/3207/3033028643_fc77090c5b_b_d.jpg

I chose to use neoprene because it was hard to make a sturdy pouch from jersey fabric, because it tends to stretch out and needs to be sewn quite tight to keep the conductive contacts in good contact with the battery. I also tried non-stretch cotton fabric and it worked well, but frayed a great deal. Neoprene is cool to work with for many reasons and also looks good in photographs.

Cut out pieces of stretch conductive fabric and fusible to match the pieces shown in the stencil. To make it easier for yourself you can first fuse a patch of fusible interfacing to a piece of stretch conductive fabric and then trace the pieces and cut them out.

With an iron set to medium-high heat (test on a scrap piece to get the temperature right) iron-on the pieces of conductive fabric to the neoprene. The conductive fabric will change colour under the heat, and to a certain degree this is okay, but if it gets too hot it will scorch and get brittle and is no longer stretchy.

Step 3: Sewing Loops

Check your local fabric accessory store to see if you can't find some interesting metal fasteners. I found some nicely designed hooks and loops that are easier to sew than the traditional kind.
Thread some conductive thread and take it double if you like. Sew on the loops to the patches of conductive fabric (illustration stencil cf2, cf3). Make sure you get about 3-5 stitches per hole of each loop. And make sure you don't just go though the conductive fabric patch but also through the neoprene, since this will be where all the weight of the batteries pulls at and it should be a very sturdy connection.

Step 4: Sewing Pouch

Thread your needle with regular thread and sew together seam 1, as indicated in the stencil illustration (see step 2). To make the seam look nicer you can sew it together with the outsides together. And then, before proceeding, turn it inside out to be the right side out.

Next sew together seams 2 and 3.

And finally sew seams 4 and 5, and 6 and 7.
(Seams 5 and 7 are only indicated once because they are a corner that should be sewn together to itself)
For a nice look along these final seams, don't go all the way through the neoprene but only perforate the outer layer of jersey and the neoprene of each side and stitch these together.

Step 5: Velcro

If you don't have any super sticky Velcro handy then you will have to sew both patches on. Just around the edges will be fine. The sticky stuff is very convenient, though tends to be stiffer and does not stay stuck on forever.

Step 6: Plus Minus

If you have any t-shirt transfer lying around then use this. Otherwise a permanent marker directly on the neoprene will also work.
It is useful to permanently mark your plus and minus poles, so that you can work with them when you make your projects. But up until the point you mark them it really does not matter which is which.
With the t-shirt transfer you don't even need to use the printer, just draw straight on it (preferably with a permanent marker) and then place it upside down and iron it on and peel away the backing. But better read though the instructions on your t-shirt transfer first, they might be different from mine.

Step 7: In Action

Now the fabric battery pouch is finished, but we need to make sure that it is working. That the connections are good and not short-circuited. If you put in a 9V battery in and your poles are touching then it will get hot, fry your conductive thread and smoke. So it is good to test it first with this in mind. And basically it is good to pay attention every time to what happens when you first put batteries in because seams can come undone, conductive threads can come loose&.
So if you don't have a multimeter handy, then you can still test it with the battery, but be prepared to take it out again fast.
And, if everything seems to be working then& then you need a circuit to hook it up to& ?

For purposes of testing the hook and loop connection I made a little sample.

ENJOY!