Ah, joy of joys, my laptop just told me that the battery needs servicing, as it's down to 79% of original capacity.
Chances of me taking it to an apple store? Zero. Chances of me buying a cheap replacement battery from ebay/aliexpress?
Close to 1, unless anyone knows of a reputable, quality supplier to the UK of replacement 2020M1 13 inch Macbook Air batteries?