Anyone using a generic PSP battery?

I see generic PSP batteries on Ebay all the time for dirt cheap. They claim to last much longer than the stock battery, but it seems kind of dodgy. Plus I hear in some reviews that the PSP cant detect the charge level on those (meaning it always says 0%), and sometimes it will just shut off the PSP for no good reason at all even if the battery isnt empty, not something i'd be forgiving of if it happened during a firmware update...I would like to save a couple of dollars so I don't have to buy a 2200, but if these batteries are a risk ill definitely pass.

So if you use one of those batteries, how is your experience with them?

EDIT: Here are some links to the batteries I am talking about...

http://cgi.ebay.com/Sony-PSP-2600mAh-Battery-Last-40-Longer-in-USA_W0QQitemZ110096771545QQihZ001QQcategoryZ122516QQrdZ1QQcmdZViewItem

http://cgi.ebay.com/LONG-Life-3600-mAh-3-6V-Lithium-Battery-for-Sony-PSP_W0QQitemZ250090020378QQihZ015QQcategoryZ122516QQrdZ1QQcmdZViewItem

http://cgi.ebay.com/3600mAh-Battery-for-Sony-Double-PSP-110-Playstation-New_W0QQitemZ120093015142QQihZ002QQcategoryZ122516QQrdZ1QQcmdZViewItem

Bump, need more opinionsFrenziedRaldo24