MacBook Air 11.6 2015

Yes. (or Maybe) some will. Depending on availability.

They may. Also main Apple Support links could direct you.

Perhaps in a circuitous path? LOL

Sometimes from experience with products, users may prefer

the quality of newertech/nupower and OWC support service.

(there isn't much warranty after whatever max for UK or EU)

Take care & happy trails!🐶😻

With an appointment they should be able to.

You also may ask if the locations in region may

or are able to accept 'mail-in' repairs, and what

that may entail, if so.

First link suggests certain prices for services.

Both have useful information of further depth.

• Mac Repair - Official Apple Support

https://support.apple.com/mac/repair/service

..to see if your location may qualify for 'mail-in' service, ask..

• Apple Repair and Repair Status Check - Official Apple Support

https://support.apple.com/repair

+ etc

• Apple - Find Locations

https://locate.apple.com/

Good luck & happy computing!🌻

Doubtful there would be any AppleCare plan on older/used mac.

You may be able to locate a good source of newertech/nupower

batteries from an affiliate of OWC (US company does business in UK

and EU through local or regional sources)

UK: https://www.megamac.com/collections/owc

Example: search results indicate batteries; various models.

Their US Site has instructions to install stuff. ~ While UK??

• DIY Battery Replacements for Apple MacBook Pro, MB/Air, MB:

https://eshop.macsales.com/shop/Apple/Laptop/Batteries

Apple 'locate pages' can find most any Authorized service/sales in

global sense: from this page: https://locate.apple.com/findlocations

So where they are, even 'independent authorized' service, should appear.

Good luck & happy trails!🌞🎣