Question about OEM Battery for Macbook Pro 15 inch Retina (2012/2013) (A1398)

No, these are not the original Apple batteries. The original ones are much more expensive.
But personally I changed the battery of 2 computers that are more than 10 years old, to give them a second life. And I didn't want to buy the originals because of the price. So I installed this battery, and it's holding up well at the moment. I don't know if it'll give me another 10 years, but in any case, between an original that's 10 years old and no longer holds anything and this one, I chose this one...

to quote wikipedia : An original equipment manufacturer (OEM) is a company whose goods are used as components in the products of another company.

Apple don't make their own batteries, most manufacturers buy them from Sony or Panasonic and then have them package it the way they need it with the right connectors etc. So this is basically what Apple buy's from their supplier, hence the OEM bit. You can buy the battery from apple but they will charge you an extra fee. think of it like buying tyres, you can buy Dunlop tyres from any ol' shop or you can buy them from BMW, guess which will cost you more :)

for what it's worth it worked perfectly for me, but removing that double sided tape that glues the bugger down is whole other pain.