Macbook Pro 5,1 2.4ghz (Late 2008/early 2009) Additional 2GB RAM recently installed (now at 4GB) Now running Snow Leopard. Started noticing it would just turn off with no low battery warning. Would start back up from battery ok, but then would soon just shut off again. Seems to run fine off mains. Tried the reset method of removing battery and mains and pressing power for 5 secs +....no joy. Here are my power details: Battery Information: Model Information: Serial Number: (serial number removed) Manufacturer: SMP Device name: bq20z951 Pack Lot Code: 0000 PCB Lot Code: 0000 Firmware Version: 002a Hardware Revision: 000a Cell Revision: 0100 Charge Information: Charge remaining (mAh): 1701 Fully charged: No Charging: Yes Full charge capacity (mAh): 2252 Health Information: Cycle count: 305 Condition: Check Battery Battery Installed: Yes Amperage (mA): 384 Voltage (mV): 12300 System Power Settings: AC Power: System Sleep Timer (Minutes): 60 Disk Sleep Timer (Minutes): 10 Display Sleep Timer (Minutes): 15 Automatic Restart On Power Loss: No Wake On AC Change: No Wake On Clamshell Open: Yes Wake On LAN: No Current Power Source: Yes Display Sleep Uses Dim: Yes GPUSwitch: 2 Battery Power: System Sleep Timer (Minutes): 15 Disk Sleep Timer (Minutes): 10 Display Sleep Timer (Minutes): 15 Wake On AC Change: No Wake On Clamshell Open: Yes Display Sleep Uses Dim: Yes GPUSwitch: 2 Reduce Brightness: No Hardware Configuration: UPS Installed: No AC Charger Information: Connected: Yes ID: 0x0100 Wattage (W): 85 Revision: 0x0000 Family: 0x00ba Serial Number: 0x006f1184 Charging: Yes Installed iStat Pro widget and it says the battery health is at 48%... does that mean it needs replacing? I cant seem to do a calibration of the battery as i cant seem to run it down, as the machine just cuts off before all power in the battery is depleted. I know others have had probs with batteries after installing Snow Leopard, so just wanted to check it whether it was a legitimate case for a new battery or a problem with Snow Leopard?