To save battery life on barracuda X, should i increase volume on the headset or PC?

I am wondering something, if i want to reach the same sound level lets say that number is X

I can get to it in two different ways

1) max out the volume on the headset wheel and then maybe 10-15% of 100 volume on PC

2) have the volume wheel on the headset at about 50% but then volume on PC has to be about 30% to match the same volume level

could anyone tell if there is any difference that one method eats more battery then the other or is in the end its all about the volume level?