Batch Render Vray Question

[Bg1137]

I'm trying to render a large HD spherical rendering to make a 360 tour. When I render one image it takes under an hour, but when I launch the batch renderer it takes 12 hours to render the same scene. does anyone know why?? I have gotten around this by rendering it as an animation, but would the bath renderer be faster if I waited it out?

Thanks!