Batching DrawElements... Efficient?

I am finding ways to speed up rendering with VA. I thought of batching several DrawElements together, is that possible? So far my Renderer can take vertices, indices and render them using a single DrawElements call. Also, it Locks/Unlocks the array (CVA), if available, will compiled vertex arrays speed up the rendering more? I have not seen a difference.

Anyway, my main concern is batching up. Any ideas?