My battery is about to die and I really need a new one.

I found these on ebay and the price is great but I don't know if they're safe to use.
http://cgi.ebay.com/850mAh-Battery-w-Tool-for-Apple-iPod-5G-Video-60GB-80GB_W0QQitemZ330191616006QQcmdZViewItem

Should I get these?
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2 schools of thoughts ---

1 - Some wouldn't think of buying third party batteries, their iPods are too precious, their priced posession, or simply 'coz they can't be bothered to change the battery themselves, which is not a trivial task.

2- Some of us are natural tinkerer and by principle alone can't phantom paying someone good$ to swith in a stinking battery. We know how to look for signs of a bad battery: gets too hot, gets fat, irregular charging etc. Most of us own tiny tools and a soldering pencil.

Yes, I changed my own battery from an eBay buy, look for my thread at the discontinued/mini forum, been almost a year now, ALMOST messed up despite my (click my sig if yer interested for my C.V.)... but would do it again.
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