If you fall outside a warranty period, Apple has a set fee for battery replacement. In the U.S., it’s $129 or $199 (plus tax), depending on the model.
Here's what to do if your MacBook Pro or MacBook Air battery is dead and it won't change, or if the charger isn't working. By Karen Haslam Editor, Macworld NOV 13, 2023 8:46 am PST
Battery replacement cost I have a 13 inch early 2015 MacBook Air and the battery needs replacing even though it says service battery, it dies at 100% and doesn’t
MacBook Air 13.3" (Early 2015) MacBook Air A1370 MacBook Air A1390 MacBook Air 13 A1932 (Late 2018) MacBook Air 13 A1932 (Late 2019) MacBook Air 13 A2179 (Early 2020) MacBook Air 13 (Late 2020) MacBook Air 13" A2337 MacBook Air MB543LL/A MacBook Air MB940LL/A MacBook Air MC503xx/x MacBook Air MC504xx/x MacBook Air MC505LL/A MacBook Air MC506LLThe price of this part is also absurd. Apple won't sell the battery alone, says Goldheart. You have to buy a new top case as well. It'll cost you around $500. and, of course, you've wasted a perfectly good keyboard in the bargain. iFixit doesn't yet have a replacement battery for the new MacBooks, but generally, its batteries run at $100 or less.