Viking shield bash

[Metathron]

This skill reads:

Gathers momentum and runs in a straight line into the selected enemy, inflicting 3-5 damage with probability of 50% to stun the target for 1 rounds. Receives an additional 1 AP for each cell traversed during the charge. The charge requires at least 1 free cell.

When my vikings have 1 action point left, and the enemy I want to attack is 2 hexes away in a straight line, I can perform the shield bash.

However, in my current battle, there are 4 hexes between them and my vikings have 3 action points left and the shield bash cannot be performed.

Am I misreading the description? I took it to mean you can run 3 + 3 action points and shield bash an enemy but apparently not.