Chosen Solution
I’ve looked through old forums and all they said was to reset to PRM or SMC. I’ve tried both several times with no luck. When I first got the new battery, it wasn’t charging, but after fiddling with the cable, it charged up to 23%. However, I unknowingly unplugged it and it went down to 8%. Now, it’s slowly decreasing and it’s at 5% now. And the magsafe won’t turn green. I suspect it’s a problem with that, but I don’t want to spend money on a new one (because this is already a new one)
I had a similar problem with my MacBook Air once. It would not charge with any MagSafe charging cable. To fix this, I had to replace the I/O board on the MBA. I would recommend the same fix for your Mac. MacBook Pro Unibody DC-in Board (part) Guides for different models can be found by scrolling down to the ‘Replacement Guides’ section in the linked page above^
