New replacement battery for MacBook Pro 15" Retina (Late 2013-Mid 2014) Battery. 

I purchased this due to a mixup and now I can't return it. It is unused.

New in box, unused and as it came. Originally purchased from trusted repair brand iFixit, the original listing is here: https://store.ifixit.co.uk/products/macbook-pro-15-retina-late-2013-mid-2014-battery?variant=31670683861041

Collection only from near Thetford, Norfolk, UK — I can't find a courier which will accept lithium iron batteries.

Note that this is the PART ONLY and doesn't come with the repair kit. I actually found the repair much more straight forward than iFixit described. You don't need to disassemble the entire device. Just use some guitar string or cheese wire to cut through the adhesive under the old battery and pop the new one it.

Supplier's technical details:

SPECIFICATIONS
Battery Model #A1494
Watt Hours98 Wh
Voltage11.26 V
Milliamp Hours8700 mAh
ManufacturerAftermarket

DESCRIPTION
If your MacBook Pro 15" Retina (Late 2013-Mid 2014) shows a "service battery" warning, shuts off suddenly or won’t turn at all, the battery is dead. For these models, the two year warranty is probably not valid anymore. Is it really time for a new laptop?

New power for your MacBook Pro 15" Retina
Not at all. Our kit includes everything you need to replace your dead battery. Even DIY beginners can accomplish this repair with our step-by-step repair guides. And if you choose the Fix Kit option, you’ll also get all the tools you need for this swap.

Don’t give up on your trusted laptop – instead, repair your MacBook Pro on your own. Why spend a fortune on a new device when your current device still works perfectly?

DIY, not shopping
Admittedly, there are easier repair jobs than a battery replacement in a MacBook Pro 15" Retina. But we're here to help! Even beginners can do this replacement with the help of this complete kit and our DIY repair guide and bring their laptop back to normal.