did some testing with my multimeter and this is what i got :
Front Of Car, Car Off : 12.4
Boot Of Car, Car Off : 12.4
Boot Of Car , Car Off, Headlights on : 11.9
Front Of Car, Car Off, Headlights On : 11.9
Front Of Car , Running : 12.0
Boot Of Car , Running : 12.0
Boot Of Car, Car Running, With Lights : 11.7
Front Of Car, Car Running , With Lights : 11.7
Front Of Car , Car Running, With Lights , Stereo : 11.7
Boot Of Car , Car Running , With Lights , Stereo : 11.7
Boot Of Car , Car Running , With Lights , Stereo , Power Windows Going Down : 11.6
Front Of Car , Car Running , With Lights , Stereo , Power Windows Going Down : 11.6