Battery is completely shot on my MBP. Will die randomly at around 20 %, less than an hour to go from 100 to 20 % on normal usage (email, browsing) and low brightness, many times it won't charge, many times it will say it's charging but it will still gradually drop in percentage. So gonna get the A1321, 1) this is compatible to my model? Seeing rather easy tutorials on iFixit, I figure I may as well do more work while opening it up. Gonna pass on RAM due to budgeting; not gonna use it for anything besides text-editing, browsing, it's basically for lectures/school use only. I use a desktop at home. NEVER use the optical drive, so I'm thinking about putting a second HDD there, possibly SSD (for instance the OWC Mercury Electra 3G SSD). 2) Any reason not to do this? Would be rather small (again budget), probably 120 GB, but sufficient for an installed OS and more. The original HDD will be for storage/backup. 3) Since experiencing battery issues it's also become increasingly noisy and performs horribly. I'm going to clean it of course, fans, logic-board, etc. Could it be that the original HDD is damaged, too, hence the noise? If so, wouldn't be that expensive to replace with normal HDD not SSD -- which requirements does the HDD need to fulfil to be compatible? 2.5", RPMs, other? 3) I need screwdrivers: Phillips #00 and 5-point Pentalobe. Both are 'normal' small screwdrivers available at your local hardware store, no? Thanks, guys!