Using a 3s lipo and UBEC - Will it last longer

[Gee]

I guess I got myself a little confused. More realisticly it would be a 3s lipo pack as the receiver pack. I used a 4s as an example to see if it would get twice the amount of time. Easier math for me.

I was thinking that a 4s 14.8v on a bec that provided 6v to the rx would take longer to reach the lvc then it would a 2s 7.4v doing the same job. Just to round the numbers off with a 3v lvc a 4s would be 12v (2.8v) and a 2s would be 6v (1.4v). It should take longer to used 2.8v. I know there's an amp thing going on here. I am just trying to avoid understanding that part of it.