old thread, but anyway: experimenting with this is extremely dangerous!
i had 2 examples in my neighborhood:
1 burned his bed because of a battery starting to burn while loading, he only noticed, because his dogs began to bark
the other one burned down his house, because of an exploding battery while he was sleeping.

better spend 20 bucks more on your battery and charger, it can save your house and your live.

just my 2 cents