Batch operation wrappers individual operations into a single operation, so it saves time for CPU. But as far as I see, most applications spend the major time on I/O cost, so CPU time saving does not seem so greatly, unless your store the databases pure in-memory.
But since operations can be in batch, you can sort your key-value pairs before putting, and this usually helps in performance. So have a try to see if this works.
Winter, Oracle Berkeley DB