Siege battles..

When I siege a city/fortress and fight the battle I use a lot of artillery to cause the defenders heavy damage. But when my ammo for artillery runs out and I have not entered the city/fortress before they do I lose the battle.
So .. This is not actually losing the battle .. I just run out of ammo ...
I could return the campaign map and try to assault the place on the next turn .. That way I could use artillery to smash the place on the first assault and next turn to bring knights to take the place ..
It would be more historical cause in medieval times it took lot of time to conquere well defended fortress ...

Also .. this is very good chance to destroy enemys infrastructure whitout taking city and losing a battle. ..

I use a similar tactic for heavily defended cities but instead of quitting after my artillery have fired off their ammunition I have my assault troops in a separate army waiting off map as reinforcements.

That way as soon as my artillery have finished firing I tell them to withdraw from the battle, and they are replaced by the assault troops I need to storm the breaches.

This saves time and avoids your general having to accept a nominal defeat on his record.

The point ot note is that the auto loss is triggered, as you stated, by your artillery running out of ammo. It is because they have run out of ammo before the way is clear to the settlement's city square and no other viable siege equipment is available (thus there is no way for you to win the battle). So you have to watch multi-walled settlements or at lease wait a turn to build some rams and ladders...

... or keep a single siege unit in reserve, with at least a single shot of ammo remaining. Then send in the reinforcements, which hopefully consist of heavy assault infantry. This shouldn't really be a problem.

Personaly, i always build at least a ram, even though i never use it. So in that case, i'm potentially able to enter the city even when running out of ammo.

The Imp

The first thing you do with the artillery is to blast a hole in the wall. These will make the AI unit 'retreat' off the walls. Sometimes they stand just behind the 'hole', allowing you to blast them with ballistae or other artillery, and they won't sally.

Since there is already a hole, you won't lose even if you run out of ammo.

Too many holes and they retreat back to the square, so I usually open 2 holes, and blast any AI troops I can find with my trusty ballistae, till it runs out of ammo. THEN i send in the troops.