Internal batteries for Sony PSP being sold on Ebay from China/Hong Kong claiming higher than standard 1800mAh capacity is not so.

My genuine Sony PSP-110 1800mAh battery when fully charged is reported at 6h 28m life by the PSP.
Three supposed PSP-360 3600mAh batteries from HK when fully charged all report 5h 20m life, which equates to 1485mAh.
Two supposed Sony Stamina  PSP-280 2200mAh from HK when fully charged report 5h 4m & 5h 23m equating to 1410mAh & 1498mAh.
Some advertised as Lithium-Polymer when they are in fact Lithium-Ion.

Ebay should clamp down on these items on plain misrepresentation...
Item might be worded as "Official Sony PSP... battery", which is not the same as "Sony PSP... official battery" (or "... Sony battery").

On the plus side, the batteries are cheap and they do work.
You can typically get 3 of these batteries (15hrs life) for the price of a real Sony Stamina PSP-280 2200mAh battery (8hrs life).
Just don't expect capacity/life of any of them to match that stated.
I have eBay member feedback that the number of recharges before failing can be a lot less too.

I would ask you NOT to leave positive feedback if you buy, but neutral or (strictly speaking) negative (false selling item).
Please mention battery life of your genuine and fake batteries in the feedback.
That way, sellers might change their ways (and listings); guaranteed they won't if you don't!

PSP Battery Information Howto

Ensure PSP mains adapter unplugged.
From PSP main menu, scroll fully left and down to System Settings, then down to Battery Information.
It will show percentage charge level and battery life left.