iFixit.com has a great guide to replacing the battery on those units, and will sell you a new one for $70. Could be a great project for you and your son, too!

iFixit.com has a great guide to replacing the battery on those units, and will sell you a new one for $70. Could be a great project for you and your son, too! https://www.ifixit.com/Guide/MacBook+Air+13-Inch+Mid+2012+Battery+Replacement/10950 https://www.ifixit.com/Guide/MacBook+Air+13-Inch+Mid+2012+Ba...