Running USB devices on batteries?

[PIGEON]

I just came across these ridiculous things:

They are gloves with a heating element that gets its power from the USB port of a computer. Did make me think of how nice it would be to have heated gloves for winter riding though. Trouble is, my bike doesn't have a USB port. And even if it did, the cables would be kind of annoying. So is it possible to run these on batteries? And what kind of batteries? I know nothing about volts and amperes or even which is relevant to get it working.

I would tansfer the heating elements from these to normal winter cycling gloves in case you thought I'd show myself in a public place sporting these bum gloves/mittens

 

[xerxes]

Here you go: http://en.wikipedia.org/wiki/Universal_Serial_Bus

Power is 5 volts. You could use a USB extension cable and cut of thw male end: http://www.audiospares.com/product.php?productid=636

A battery holder: http://www.rapidonline.com/Electrical-Power/Batteries/Boxes-Holders/C-Cell-battery-holders/73630

4 x rechargeable NiMH batteries would give you about 4.8v, so should work: http://www.rapidonline.com/Electric...ide/Rechargeable-NiMH-batteries-Hi-Watt/80861

Put it in a box: http://www.rapidonline.com/Tools-Fa...ases/ABS-Boxes/Miniature-ABS-boxes-Teko/62567

Maybe run the USB cable through a gland: http://www.rapidonline.com/Cables-Connectors/Cables/Cable-Glands/Euro-index-cable-glands/66913

Add a switch: http://www.rapidonline.com/Electron...r-Switches/SPST-Miniature-rocker-switch/31451 and maybe a waterproof cover: http://www.rapidonline.com/Electron...aterproof-cover-for-round-rocker-switch/75723

I don't know how long the batteries would last, what's the current draw of the gloves? It can't be that much, USB 2.0 can only supply a maximum of 1500mA.

 

[xerxes]

Have a look at these as well:

http://www.ladyada.net/make/mintyboost/index.html

http://hackaday.com/2005/01/20/how-to-make-a-usb-battery/

http://www.instructables.com/id/Double-Capacity-MintyBoost-with-4-AA-Battery-Holde/#step1

http://www.portablepowersupplies.co.uk/usbliionbatterypack.htm

 

[Carge]

Or how about, rather than running it off batteries.....
.... running it off a dynamo!

I think most bike dynamo run at 6V - but someone clever could probably step it down to 5V.

I've sat in the garage on the turbo in the winter, wondering if I could recharge the USB-rechargable lantern while I spin the wheels

 

[cyfa2809]

why dont you just buy those heat pads that you 'click' the element in them, they heat up for 8 hours or so
no volts! re usable!

 

[sic_nick]

Heated grips

http://www.amegrips.com/category/catalog/mountainbikeheated

 

[legrandefromage]

dynamos generate alternating current, you'd need a rectifier of some sort.

 

[kaytronika]

Would be interesting in inclement weather.

 

[Iwasgoodonce]

Don't scratch your nadgers in the rain!