For me I'm not sure.
Seige = 1x, 2x, 1x, 2x, 1x, etc.
Battle = 1x, 1x, 1x, 1x, 1x, 1x (get on the good team) 2x, 3x, 4x, 5x
Seige switches back and forth (due to team balance, and switching attack/defending teams)
Battle depends if you get on the "good" team or not. If you do, you will get 5x. If you don't (cuz everyone else is trying to get on that team too) you will be stuck on 1x.
However, Seige is the best place to get game experience (become a better player) because you have more opportunities to fight and dont have to wait to spawn.