Also the risks are that the battery might get too hot and the electrical currant may conduct through the case I would but a rubber layer over the sides of the casing or any material that doesn't conduct this would reduce any risk of shock
If you use a longer the spring the shorting point will be smaller therefore reducing the heat but a weak resistor could help but may be hard to control the heat and power output
I also might have a longer spring. I wonder if that might get more heat (or dispense heat differently).
Thx. I wonder if putting some weak resistor in the circuit could both extend the battery life a little and reduce some risks. BTW, besides maybe hard to control heat, what are the other risks involved?
You can get heat for about 30 mins off a half used battery but it is entirely up to the charge of the batter
About how long do you get heat? I have a bunch of half-dead 9-volts and this seems like a nice way to get some use out of them before they go to the battery recycling place.
Thanks I just edited so I don't get blamed thanks for the tip my first instructable so I was so worried how people would react
Nice idea, but I would put a disclaimer in their, letting people know its not your fault if they get hurt. Shorting the battery like that could possible cause problems. Just better safe than sorry ;)

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