I've got a 2012 Retina MacBook Pro, which has two problems: a battery that might last 20 minutes if you're doing nothing much, and a trackpad that sometimes doesn't respond.
I bought it second-hand for Mac software development purposes, but it's finding other uses too. It was sold as having a fault with the screen intermittently flickering black, sometimes enough to make it unusable, which I don't think I've ever seen. Because of the fault it was going cheap – otherwise I would have bought something with rather lower specs. But I've found these two problems with it (I didn't realise at the time that the battery was quite that bad), and while I don't mind the battery problem, I strongly object to the trackpad problem...
With regards to the trackpad problem, I have read that the battery could be responsible if it is swelling or similar. I will note that the problem only seems to appear when it is fully charged, and particularly after it has been fully charged and plugged in for a while. So I'm thinking this is likely, but I'd like any thoughts on this.
With regards to the battery, I know about the difficulties of getting out the existing thoroughly-glued-in battery, but I'm willing to attempt it. I'd like a better battery life, but don't need it. And if it fixes the trackpad, then it is essential. And any other problem with the trackpad would require removing it anyway, so it might as well be replaced. The question here is, does anyone have any recommendations for getting a replacement?