|Chances are, yes, the default battery settings need to be changed.|
on Windows 7, click the Start button, then type "Power options", and click that. Then, select the "High Performance" option, and click save.
If that doesnt fix it, or you already had High Performance selected, click "Change Plan Settings", then "Change advanced power settings". You'll have to go throughout all the options, and, when given the option to set something different settings on battery and plugged in, change teh battery options to exactly the same as when plugged in,
Be careful, because this may reduce battery life.