Quota Exceeded - batch requests webmaster console

[Matthew Williams]

I'm attempting to batch up a number of requests into one call.  I'm using the Python libraries to do so.  The problem is, the response I'm getting back seems to indicate that the requests are coming through too quickly.  Which is WHY I'm using the batch request to begin with.  What I'm seeing is:

<HttpError 403 when requesting https://www.googleapis.com/webmasters/v3/sites/https%3A%2F%2F<sitename>/searchAnalytics/query?alt=json returned "Quota Exceeded">

This message appears randomly in the result set returned back.  Running the same batch repeatedly and the message happens at different times within the batch.  But out of 2500 requests about a dozen will randomly work correctly while the rest all fail.  If my batch size is 3-5, it works fine.  Anything over that and I start seeing the above message.  Does anyone have any clues on this?  This seems to defeat the purpose of even having a batch request if you cannot send a batch request successfully.