Find powerful battery for Samsung AA-PB9NS6B

Hello

I am looking for a powerful (> 4400mAh) battery for my Samsung AA-PB9NS6B. The reason for this is that My IPC laptop can charge the battery on AC power only up to about 20% and

only very slowly. The unit is about 3 years old.

So far I've found some links:

http://www.batterietutti.com/samsung-aa-pb9ns6b.html

http://www.buonabatteria.com/samsung-aa-pb9ns6b.html

Unfortunately there were no hits at Samsung AA-PB9NS6B.

Now my questions:
First Do you know where to find some perhaps such a battery?
Second Would you in the above shops to buy something?

greeting