ASUS 90-NED1B2100Y G50 / G51 / M50 / L50 / M60 9-Cell Battery (black)

Pros: Not much to say, it's a battery, it lasts longer than the standard 6 cells on the M50 series. (2.5hrs vs. 4+hrs)

Cons: It expands the laptop base about 1 inch out due to the size, which kinda defeats the purpose of having it more portable, by putting more bulk on your laptop. Expensive.

Overall Review: Get this if you need to last 4 hours w/o charging. Just get this and use your standard 6 cell for a spare.

Pros: It works and adds considerable life to your notebook. About 3 1/2 to 4 hours on battery saving with mine (Asus G50v).

Cons: It does stick out of the laptop about an inch but it doesn't provide much problem and is worth it for the life. You may be able to find it a bit cheaper, but not by a whole lot.

Pros: None

Cons: DOA, won't hold any charge

Overall Review: I bought this battery to serve as a spare. I did not buy it from newegg since newegg wasn't carrying it at the time of purchase. The battery arrived DOA. After literally weeks of back and forth with Asus support, they finally decided that the 1 year warranty does not apply to batteries bought separately from a laptop. So BEWARE, Asus WILL NOT REPLACE YOUR BATTERY IF IT IS DEFECTIVE. Not even if it's completely defective out of the box.