Battery charges. MBA does not use battery power. It must be plugged
Battery charges to between 98% and 100%. MBA does not use battery power, except for 2% or so. It must be plugged at all times. No known damage.
OS X El Capitan 10.11.1 (15B42)
MacBook Air (13-inch, Late 2010)
2.13 GHz Intel Core 2 Duo
4 GB 1067 MHz DDR3
NVIDIA GeForce 320M 256 MB