I got a short of some sort and the battery got hot!

Started by rock grl, July 28, 2011, 04:48:38 PM

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rock grl

Hi. I soldered together a pedal I made and something came lose, i.e. a short of some sort. Anyway the 9-volt battery got real hot! I was wondering what might have happened to cause this? Could the hot and ground of the battery somehow touching have caused this? 

CynicalMan



CynicalMan

That's never happened to me. If it could, it would at least take a while. I think it would be more likely just to burst. Only one way to find out!


PRR

> Could it cause a fire?

The HIGH-density batteries in cellphones and laptops can start fires.

Shorting a car battery more than a few seconds can be very violent.

The usual small disposables get mighty warm, but don't seem "dangerous". I had a 2-pound lantern battery, shorted for some minutes. It was warm enough that I would not want to hold on to it for a while, or set it on a nice varnished table, but it wasn't anywhere near fire, and hardly into the skin-burn zone.

But why ask? EXPERIMENT! Take a battery snap, extend the leads 10 feet to a switch.

Go out in the driveway.

Wear gloves and safety glasses. (just in case!)

Put the battery on a small sheet of dry (flammable) paper on the pavement.

Be sure switch is OFF. Connect battery. Step back. Trip the switch.

The shorted battery will dump ALL its energy INTO itself in a minute or so.

It will get hot.

My bet is that the paper won't even scorch.

Wait a minute. UN-short the battery.

Wait another minute (intense action may give a delayed result).

Go tap-touch the battery. We already know it is hot. I bet is is not instant-burn hot.
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darron

9V batteries are actually pretty good at starting fires!

don't keep one in your gig bag with steel wool.... or go give it a shot now if you'd like... under controlled conditions of course :)
Blood, Sweat & Flux. Pedals made with lasers and real wires!