Chosen Solution
Hi All, Just installed a new iFixit battery into my Mid-2012 15” Unibody MBP. Also replaced the DC in board and a new Apple 85W MagSafe charger. The battery is recognised and seems to work fine. However, when running on battery power the battery percentage drops down to around 50% after an hour or so and then all of a sudden it will drop from 50% down to 7% instantly. The computer will run for maybe an hour at 7% then will drop down and eventually shut down at 0%. I made sure to follow the calibration instructions to the tee, charging to 100% running it on the charger for a few hours then unplugging the charger and draining the battery until the computer shutdown. I then left it overnight with a flat battery and recharged it to 100% the following morning.
I have reset the SMC, reset PRAM. I am also using a new 85W MagSafe adaptor. Could the battery be faulty? Thanks in advance, Luke Update (04/15/2019) Thanks for the replies guys, I do get about 3 hours of use from the new battery, It seems to go OK from 100% to around 50% but it just drops from around 50% to 7% within a minute or two, then sits at 7% for about half an hour then I maybe get another half hour of battery life before the computer turns off. It has taken over 6 hours to charge it up today, much slower than yesterday (full charge in around 3 hours)..
sounds like you might have a faulty battery. Best app you can use to get a reading of the battery health is ‘Coconut Battery’ get a screen grab of the test screen on that app, then email them direct. I’ve seen quite a few replacement (non-apple) batteries have issues like this, and it is nearly always a fault with the battery. In some cases, the battery shows a full charge capacity of over 60,000 (which is physically impossible), and it powers off after a few minutes on without mains plugged in. OWC batteries have this issue from what i’ve seen, as we sell a lot of them.
