I don't know the details of the crackling chemicals, but was the battery being shorted out by all the spare change on top of it? Shorting a battery causes the chemicals to heat and expand, and thus leak.

Good question bhankii, No, I'm pretty sure it wasn't being shorted.

Electrolisis could be a cause. If you live near the sea ( High conductivity air)and have high humididty I could imagine that diferent metals and an electrical charge could do all kind of things. Hope your not hearing voices. Happy+mas. Ky.

Grab an ohm meter and put the test leads into the change dish. The change conducts for me....Do I hear Bach???

The change definitely conducts... I learned this the hard way after tossing a 9 Volt battery (both leads on the same side) into my pocket. A few minutes later, the change and battery were hot enough to burn my leg.

Ditto.

Same thing happened to me. Now when I take batteries out of their packaging and I don't use them straight away, I apply electrical tape around the terminals.

I realize that change conducts. However, I don't think the terminals of this battery were being shorted. Even if they were, when I removed the battery from the dish, the crackling noise continued. I'm sure there was a chemical reaction going on, I just don't know what it was.

I recently had a cheap alkaline battery and flashlight overheat, and actually melt parts of the flashlight.

Both batteries and flashlight wer bought at IKEA.

I suspec an internal short in the battery. When replaced, the flashlight worked well.

Some of these batteries swell when they are undergoing a chemical reaction that causes leaking. This swelling might be putting mechanical stress on the battery case or box and that might be causing the sound, in much the same manner as wood creaks when under stress. just a thought.

There might be a chemical reaction with the glaze of the dish, if it is pottery, this micht cause the glaze to expand/contract, Pots just out of the kiln often crackle, due to a thermal expansion, mis-match. Some pottery glazes use this crackelure as a decorative feature.