i tried a batch explore earlier, used enough turns to double my acres, but it wouldnt let me double up? all my stuff was built on. So what how many more acres can i add through mass explore? lets say i batch explore at 4k acres, i should be able to add 8k acres right?

This is correct. Either you did the math incorrectly, or you had an event that stopped your batch explore. Make sure you have enough food and or cash on hand to fund your batch.

Oh and obviously you need the turns :P

not sure on your wording, but you can add TO 8k acres, the 4k you held, and then another 4 you just explored..

Hmm...upon reading this again, I may have misunderstood your question.

at 4k acres, you should be able to ADD an additional 4k acres giving you a TOTAL of 8k acres.

4 k acres fully build should give you 4 k land extra after ME unless
- ran out of food?
- ran out of cash?
- ran out of turns?
- your luck is bad as acres explored per turn is less?

What else? Does earthquake halfway where it destroys the number of built land reduce the 1:1 built vs unbuilt land ratio that stops it further exploring?