Out of the box, I had some difficulty fitting the battery into the battery compartment of my old Macbook; you may have to muscle it into place. The backing of the battery is warped so the edges don't fit flush to the bottom of my mb, but that's merely a cosmetic issue (I hope). My only expectations from the battery were that it charge up and keep a charge for an hour or two. I charged it for about 12 hours, then unplugged the battery from the charger. The battery indicator on my desktop was x-ed out indicating that there wasn't a battery connected. I removed and re-seated the battery to no effect. I recharged the battery for about 4 hours. When I unplugged the charger, it lasted about 10 minutes before exhausting the charge and my macbook shut down. I next removed the battery, pressed the power button to clear any residual charge, reinstalled the battery, then recharged it for a couple of hours. I booted up, and with the charger connected, the battery allowed enough through current to keep it running, but that's the only way it would work.
The only documentation with the battery is a sheet detailing "Technical Support and Return Instructions". The headings are: For Returns, For Replacements, To place a new replacement/exchange order through our storefront. It's not confidence-inspiring when the manufacturer expects their product to be defective.