What does adding crew after a battle actually do?

Where does this crew come from?
I've never noticed if it costs anything,does it?
Don't you get full crews at the start of each battle anyway?

Do you mean naval crew or soldiers in your army?

Naval crew only gets replaced at a cost to you when you repair the ships in a port you own (hmm, can you repair a ship of the line in a trading port?), but soldiers get replenished automatically each turn at no cost to you. In order for them to receive their replenishment they have to be in friendly territory and not in an area of attrition during winter. You'll see different coloured "+" symbols next to their icons showing you the rate of replenishment (which is affected by buildings, a General's traits and ancillaries, and tech).

You don't automatically start every battle with fresh, full regiments. One or two turns of attrition to your full stack and you'll have a hard time fighting a fresh enemy stack.

Originally Posted by klesh

Naval crew only gets replaced at a cost to you when you repair the ships in a port you own (hmm, can you repair a ship of the line in a trading port?)

You can repair any ship in any of your own ports, regardless of whether the port is capable of building the vessel or not.

But theres the option of adding crew after a naval battle as well which is what I'm wondering about.

Do you mean like adding the captured ship to your fleet? The only adding of naval crew I know of is when you repair a ship in a port. Screenshot maybe?

After a battle you have the option of redistributing crew between the remaining ships in the fleet. I believe that this simply takes the total number of crew in the fleet and evens them out across the ships. I can't say that I use it but it could be useful if one of your main ships has lost a great deal of the crew in the battle and you're likely to fight again before reaching port.

Originally Posted by meme_engine

After a battle you have the option of redistributing crew between the remaining ships in the fleet. I believe that this simply takes the total number of crew in the fleet and evens them out across the ships. I can't say that I use it but it could be useful if one of your main ships has lost a great deal of the crew in the battle and you're likely to fight again before reaching port.

Ahhhh,thanks mate.