I was in the same situation with a Macbook Air 2011. At about 9 years old I needed to replace the battery, but got turned away from the Apple Store because it was 'too old'.
I tried buying a replacement battery online but it only worked for a short time before it stopped charging all-together.
Left a really sour taste in my mouth because the battery was the only thing stopping me from using an otherwise perfectly fine piece of hardware.
I tried buying a replacement battery online but it only worked for a short time before it stopped charging all-together.
Left a really sour taste in my mouth because the battery was the only thing stopping me from using an otherwise perfectly fine piece of hardware.