Wow, super crazy! Your psp only likes the origional sony charger that came with it! So, don't loose it, or your psp could explode any second!! Poor Bob Nixon, with his dead psp.... Here's his story:
"It had been charging for over an hour when it just went off." He lost his official charger during a trip and was using a generic Radio Shack charger. A shame.
" First, the scent of something burning. We all know the smell of something plastic on fire -- it stinks and the black smoke sticks to the wall like nicotine to the lungs. That's where the smoking analogy ends, since the PSP battery exploded so forcefully that "it flipped the PSP off of the nightstand." There you have it -- get an official replacement from Sony or make super-duper sure that an off-brand charger will work properly with your PSP. "

Ouch, the poor fella died in vain...
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