On RPG Biz's Facebook Community Messenger, I was asked if battle encounters count as a different map. 

Using an ABS system of fighting does not apply, because the battle does occur on the same map. 

It is possible to make a battle encounter, appear to 'be' on the same map, when using RPG Maker MV, by selecting the [None] option on battlebacks for map details.  It will give you a slightly magnified look at the closest map terrain. 

If a similar terrain battleback is used, the battle is occurring at the designated spot on the map, even though it may physically appear different within the sideview and frontview battle options for some game engines.  

So the answer no.  Using a battleback will not count as a second map.  The event is occurring at a specific spot of the one map.