MacBookAir4,2 Mid 2011: MC965LL/A (1.7 GHz Core i5)
MacBookAir4,2 Mid 2011: MC966LL/A (1.7 GHz Core i5)
MacBookAir4,2 Mid 2011: MD226LL/A (1.8 GHz Core i7)
MacBookAir5,2 Mid 2012: MD231LL/A (1.8 GHz Core i5)
MacBookAir5,2 Mid 2012: MD232LL/A (1.8 GHz Core i5)
MacBookAir5,2 Mid 2012: MD232LL/A (2.0 GHz Core i7)
MacBookAir5,2 Mid 2012: MD846LL/A (2.0 GHz Core i7)
MacBookAir5,2 Mid 2012: MD846LL/A (2.0 GHz Core i7)
Apple Part #: 661-6055, 661-6639
Printed Part #: 020-7379-A
Printed Model #: A1405
 
Mac.Infinity Tips
How to prevent swollen battery?
 
Keep the battery cool for the most part – in other words, keep it within regular laptop operating temperatures. Don’t store it in the sun or use it plugged in for long periods of time in the sun.
Use the right capacity Apple charger or quality third-party manufacturer charger.
Don’t leave the laptop constantly plugged in when it doesn’t need to be.
Replace old batteries that are not holding their charge anymore.
 
 
Battery Installation by Mc.Infinity 
https://www.macinfinity.sg/macbook-battery-replacement