Can you charge your PS3 controller with the PS3 turned off?

[Dragonfall]

I don't want to keep my PS3 on while it charges.

 

[Malice]

Why can't you charge it while playing a game?

 

[Jaxel]

Plug the charging cable into your computer.

 

[Mage]

Why can't you charge it while playing a game?

It may be his only controller; unless it is a preferred controller.

 

[Baldulf]

Plug the charging cable into your computer.

I tried that once, didn't work.