Hi there, I've been an apple product user since 2004, but was only in 2009 that I bought my first mac computer, a mid-2009 macbook pro 17 inch. 2 years ago upgraded the memory from the original 4GB to 8GB using kingston memory, that never gave me a memory error or whatsoever. Last year was feeling that my mac was getting slow to boot and while doing some tasks, so decided to upgrade the hdd to a ssd, and replaced the disc drive with a caddy to use the 500GB hdd on it for storage. No problems, never with my mac even when using OSX or Windows via BOOTCAMP to play some games. But since last november it decided not to turn on even with the ac adapter connected and battery fully charged, so decided to open it up and troubleshoot it, expecting to find the source of the problem. Removed everything, removed the battery cable and pressed the start button to release any electricity in the circuit. After so much trial and error, decided to warm up the battery with care, and it STARTED. The problem is that sometimes warming up the battery solves it, others you have to be patient, so my guess is that the battery is the problem, but could other thing be causing the problem?? Have anyone had a similar issue? If so what was the fix? I'm recurring to you, because it sometimes cumbersome and not practical to have my mac without the back screws to be easier to remove the back cover to start the computer every time. Thanks in advance.