Get this
SONY VGP-BPL2
Battery replacement now.
SONY VGP-BPL2
Battery is a spare use rechargeable Li-ion
Battery pack for laptop, 11.1V, 4400mAh made, passed strict quality certification and provide 1 year warranty.
http://www.laptop-Battery-pack.co.uk/SONY-vgp-bpl2.htm
Volt: 11.1V
Capacity: 4400mAh
Size: 206.55 x 49.40 x 19.50 mm
Net Weight: 313.50(g)
Color: Black
Battery Type: Li-ion