I saw the exhibit once. You used to be able to take a ramp or stairway into a corridor which brought you down to the level of the cat exhibit moats. Once in the corridor there were small glass viewing windows into the cat exhibits and the bat exhibit was in the corridor as well. The exhibit itself was a nondescript glass box style bat exhibit, and had either Jamaican Fruit Bat or else Seba's Short-tailed Bat (can't remember which). There was also a small aquarium with Blind Cave Tetras.
It closed sometime around 2005. The early/mid 2000s was a period when the zoo was significantly downsizing its collection. Partly this was to clear space for Asia Trail resulting in loss of the Australia House, most of the species in the elephant house (giraffe, rhino, hippo, pygmy hippo, capybara), and a few other ungulates like Malayan Tapir and Eld's Deer. The zoo also abandoned other exhibits around this time without replacement. In addition to the bats other abandoned exhibit ares were the small carnivore loop and bear grottos, although many of those species were re-homed in Asia Trail. My sense is that the additional exhibit closures were a combination of budget, safety, and animal welfare concerns.