$conf['batch_download_max_elements']
Maximum value of the Maximum number of photos per download set slider. Default is 1000.
$conf['batch_download_max_size']
Maximum value of the Maximum size of each archive slider. Default is 500.
$conf['batch_download_force_pclzip']
If true, forces the usage of PclZip instead of ZipArchive as ZIP library. Default is false.
$conf['batch_download_direct']
If true, delivers ZIP files with HTTP redirection instead of PHP flow. Default is false.
$conf['batch_download_additional_ext']
Array containing downloadable file extensions (case sensitive). Default is $conf['picture_ext'].