I've searched, can't seem to find an answer specifically for my situation. I have a Mid-2009 Macbook Pro 13.3 inch. It was running a little slow, and that's understandable given it's more then 5 years old. I bought a solid state, upgraded the ram, and decided I also wanted to put a new battery in it because the old one wasn't working very well. So, I bought an Anker one. I realize this may or may not have been the smartest thing to do, but I did it anyway, here's the one i bought: http://www.amazon.com/gp/product/B00D780NNQ/ref=oh_aui_detailpage_o01_s01?ie=UTF8&psc=1 I installed it, connector put completely in, and when i started the computer it says not charging and has an x on the battery icon, and if i click on the battery icon it says, "No Battery Avaliable." I have reset the SMC, no go. I then decided to put my old battery back in and try to return the Anker battery. Well, now my old one doesn't work either. If i put the original battery in, I get the same not charging/x on the battery icon/no battery available. Everything else works fine on the computer, I'm using it to type right now. Any ideas on what i could try to get one of these batteries working? Thanks for any advice!