MacBook Pro (Mid 2009) battery replacement
Scott S -
My old MacBook had been showing a "Service Battery" for a couple of years. The warning stated that there was no danger, but that I should bring it in for service. Resetting the System Management Controller (SMC) didn't help. The battery had several hundred cycles on it, and I ignored the warning for years since I mainly use that MacBook for projects, having upgraded to a Retina model in 2013. Eventually, the battery life became so short (less than an hour) that I figured it was worth the investment to replace the battery.
Getting to the battery was incredibly easy--10 small phillips screws on the bottom of the laptop and 2 tri-wing "Y" screws on the battery and all I had to do was carefully unseat the battery connector from the motherboard with a nylon spudger.
The battery (from "new stock") was a perfect fit and the system recognizes it as OEM with 1 cycle. Even though the charge indicator (the older models had one on the side of the laptop) showed 80%, I let the battery charge for 10 hours as noted on the battery packaging. I reset the SMC for good measure (Left Shift + Left Control + Left Option + Power simultaneously with the system powered-off) while the system was charging so I could see the charge light cycle orange-green-orange.
This Old MacBook is back up and running like a champ. A solid-state drive makes a world of difference in performance, too.
Be patient when re-inserting screws. Turn them counter-clockwise and feel for the screw to seat on the threads before tightening (clockwise)--the aluminum chassis will easily let you cross-thread the screws. Don't over-tighten. Make sure to match the screws to the holes they came from. 3 of the screws are much longer than the rest.
If you reset the SMC, make sure you press all 4 keys at the same time. It has never worked for me if I held the shift, control, and option keys first and then pressed power. I only got the confirmation (charge cable LED changes from orange to green and back to orange while charging) if I pressed all 4 at the same time.