Review on NinjaBatt'S Longlasting Battery Upgrade For Apple MacBook Pro 15" [2011-2012 Models Only] A1286/A1382 - 10.95V/77.5Wh by Mario Hernandez

Terrible product. Does not hold a charge at all. Not only did it take forever to fully charge (more than 6 hours), the battery percentage would drop from 50% to 7% instantly. This was after fully charging/depleting over a few days and experiencing the same result. Not worth your time or money. There is a reason Apple charged $129 for a battery and this one is only $55. Look elsewhere.