If your map is embedded on your website and can be shown / hidden based on a click or event on the web page, you may find that the map zoom level is improperly set when the map first appears. This is because the map is actually initializing in the background before the iframe is visible, and its not able to properly calculate the height and width of itself.
So since the map cannot properly see its own height and width, the default zoom level cannot be accurately calculated.
To remedy this problem make sure the map is either fully visible when the iframe is loaded. You could have the event to show the map also initialize the BatchGeo IFrame code by only setting the src="" attribute when its time to display the map.