My battery life is now only 5.5 hours. The Apple "spec" for this is 7 hours or so. I upgraded to ML and the battery time degraded but it seems to be running down much faster than expected. Is this becoming a bad battery ? What are other folks' stats for this ? Here's my data : Nov 2011 13in MBA being used just for normal tasks (Safari, EMail, Excel). Nothing heavy on CPU usage. Battery stats are : Health 87%. Cycles 235. Time remaining when 99% charged 5hr25min. Power info (from System Report) Amperage (mA): -1864 Voltage (mV): 7569.