My MacBook battery is swelling.
MacBook, OS X El Capitan (10.11.4), 2009 late
You need to properly dispose of that battery before it starts to leak and buy yourself a new battery like you should have done 1 year ago. Look for either Ankor or Newer Tech brands and avoid at all costs the cheap knockoffs sold on auction sites. I believe you can find both brands at Amazon.
Find somewhere to recycle - dispose of and get a new one. As stated before don't buy the cheap ones on either eBay or amazon. You buy a $10 battery and you will regret it. Newer tech you can get at OWC - http://eshop.macsales.com/shop/Apple/Laptop/Batteries?_ga=1.83293142.1972310973. 1456321979
or Anker - https://www.anker.com/products/taxons/164/Batteries
Ive had very good luck with Anker and very bad luck with the cheap ones on eBay etc.
My MacBook battery is swelling.