Are battles always one sided?

[Rich04]

Tweaking Ship/Fleet Strategy is very important.
In my 1st PBW game I lost several battles that looked even without inflicting significant losses to the enemy fleet. Upon viewing the battles I finally figured out what was happening. My ships were failing to kill off damaged ships. They would fire until the opponent was disabled and move on to the next target. The opponent had enough repair ships to fix his fleet each turn. This is the default setting for SE4 and what very often turns a battle into a one sided slaughter. If your opponent has more ships you will almost always lose without inflicting any losses, all else being equal.