Battle Credits & Ammo Crates

Are you talking about single-player or multi-player?  For single-player, there are usually ammo crates scattered around any places where a combat is going to take place.  In multiplayer, the maps all have several ammo crates scattered around the arena.  They're usually tucked away in hallways or the outer rooms.  Once you play the maps a few times, you get a feel for where they are.  When in doubt, follow your teammates between rounds.  Chances are they are all running towards a box.

Keep in mind, the boxes have a limited supply so you may not all be able to reload from the same box at once.  However they do refresh between rounds.

One thing to note about the single player is that they really do want you to move around a lot.  So while the ammo crates are there, they usually deeper in the fight.  If you're like I was, and like to sit back in cover, you could find yourself running out of ammo quickly! Don't be afraid to get in there and mix it up.

Also, if you're speaking about the very first mission, I know I ran out of ammo right at the start myself, until I got my aim back and didn't waste ammo at the start and like I mentioned a moment ago pressed into the fight more and moved around.

The one thing to note is if you hang out next to it, shoot a few round and reload and accidentally get to close to the ammo box it will refill and use up one of the charges on the box.  You could accidentally be taking up all your ammo when it's not needed.  Make sure you're actually low to almost out of ammo before hitting those boxes again!

always keep an eye out on maps for that stuff. i make it a habit to run back to cleared areas in sp to get ammo topped off before going out again. multiplayer can suck with everyone getting ammo at the same place and emptying it though. just gotta make sure whats around. im playing on normal now. insanity will be an ammo drain im sure.

If anyone is watching this old post, please help. When I approach a supply crate, nothing happens. No Y tag, as you'd expect. Is there an automatic, silent upload going on?

@Piranesi172288 

Try to repair the game. (in Origin > Game Library > right click MEA > Repair)

Yes, but in XBox nothing like this is available. I uninstalled, removed all associated files, and reinstalled, but to no avail. Everything else seems to work.

Piranes, I was having the same issue until I actually fired a few rounds and needed ammo. When I approached the box, it automatically filled my ammo requirements. Same with energy.