Can I use a soundcard for guitar effects?

Where a 3.5 mm or 2.5 mm jack is used as a DC power inlet connector, a switch contact may be used to disconnect an internal battery whenever an external power supply is connected, to prevent incorrect recharging of the battery. On some DI units and guitar effects units, a normally open switch contact on one of the signal connectors is used to connect an internal battery whenever a cord is connected. The desired effect is to switch the unit off whenever the cord is removed. A side effect is to discharge the battery if it is not removed, for example if equipment is left connected overnight.