It still seems there are a few people out there that don't know the MacBook Battery, along with ALL MacBook batteries can easily be changed.

The cost for a new MacBook Air battery is $66 on eBay, so please give it a rest that it can't be changed. That's a lie and you know it...

So in 3 or 4 years when it needs changing, just do it, quit complaining about something you know nothing about.