Essentially all that would happen, is that during every interval of 3 minutes or so; a small convoy, would have to be protected. Then the amount of power cells that a team gains is influenced by how many vehicles successfully make it to the base without being destroyed.
Once the convoy arrives, then the power cells would spawn at the base, and are free to be spent on any tower. The convoy would likely consist of 3 transport vehicles, and an optional 3 defending battle tanks.
EDIT#1: In order to prevent spawn camping It's also suggested that convoys have alternating spawn locations. Spawn locations should also be positioned slightly closer to the allied base than the enemy base and spawn near the edge of the map.
Edited by Livaria, 29 April 2017 - 11:42 AM.