Please add language option by using COM_getLanguageId() and use ssl api url for SSL site.
did it for me.
see more
https://github.com/ivywe/geeklog-ivywe/commit/165b0c065061cfc2d4e33c65ef27bc7209cb7834
Google maps api url for SSL
see more
https://groups.google.com/forum/#!topic/google-maps-api-japan/DFS3VvQSwlA
thanks.