How effective are base defense batteries?

[aplomado]

So, if I have a base with no soldiers, can it be defended with the base defense batteries adequately (plasma ones)? How many ones would be needed to prevent the aliens from taking it?

[BULIGO]

I support OP's question.

Back in UFO - EU. I relied heavily on base defences. I remember there was a formula where if you built (I think 4?)enough Fusion Ball defences, there was a chance one in a 100.000 attacks that an enemy battleship would get through.None got through in any of my bases. It was getting old a bit. I kinda would prefer to actually perform airtight air superiority and shoot down any marauding UFO heading for my base instead of paying maintenance for stuff I need every blue moon.

[LKx]

one time with 3 mag turrets, 2 missed and the last one shot down the big ufo

[ntalas]

It's base defence has a percentage chance of hitting the target. Then it can inflict some damage. I had two plasma defences in a base. The first one missed, but the second one destroyed the Cruiser. Larger UFOs should be harder to destroy.

I don't know the statistics of either the defences nor of the UFOs, so I would say that four defences in each base and the fact that you don't play Ironman, should be enough

[Drew]

I had three plasma defenses miss the incoming medium ship, and there being no soldiers there, the entire base was lost... 5 planes all in various states of refueling/rearming after sorties... it was an awful lesson.

[Max_Caine]

Defences only have a 60% chance of hitting. So while they do plenty of damage, you have to have a dedicated set of batteries to be any good. Thankfully defences auto-upgrade, so you don't have to rebuild defences which could potentially be useless.

[Dranak]

Assuming your tech level is up to par, one battery does enough damage to 1 shot the relevant ship that does base assaults. But they actually have 50% accuracy, so if you build them I suggest at least 3 (4-5 would be better).