Please help, HP Pavilion dm4 laptop problem?

hello, all. when i was playing games, my HP Pavilion dm4 laptop screen turned black. one of my friends told me that i should replace the battery. He said that he met the same problem with me. i would like to buy one from a online shop, because it is much cheaper. i have found two, but i do not know which shop is better. can you give some advice? thanks in advance.

http://www.cbattery.net/hp-pavilion-dm4.html

http://www.batterymag.co.uk/hp-pavilion-dm4.html