I recently upgraded my Macbook Pro (was bought in 2006) with a bigger hard-drive, more RAM, and installed Snow Leopard. (10.6.8) I also got a new battery because my old one was only holding 40 minutes of charge (while computer is idling) which is not enough for my uses. Before I go on, here are my system specs: Macbook Pro (late 2006) Mac OSX 10.6.8 2.33 GHz Intel Core 2 Duo 4 GB 667 MHz DDR2 SDRAM ATI Radeon X1600 My computer shuts down when the remaining battery level is at 5% exactly. It happened with the old battery as well and before I installed all of the upgrades. I have tried numerous solutions, including resetting the SMC and PRAM. For both batteries I recalibrate them properly every 1-2 months. The new one only has 6 cycles on it (just installed it a couple of days ago.) and I still have this problem. It gives the 'low battery warning' at 10% like it should, but then it just shuts down at 5% and does not go into its special sleep mode. When it shuts down, I try to reboot it but it does not turn on -- almost like the battery is completely depleted. When I plug in the power adapter to start charging it, only then can it boot-up. But, even then, none of my work is saved like it would have been in the 'safe sleep mode'. Again, I already tried resetting the SMC and PRAM, but that did not work for either batteries. Please provide me with other solutions. (Oh, and obviously my Mac is out of warranty considering I bought it 5 years ago.) Thank you.