Currently the only option is to download all data. It would be nice to be able to export/download date using a date range or at least a start date.
The move to Amazon Web Services required a rewrite of the data export feature to get around some limitations. I had to create the exports to be downloaded by month. http://support.teslafi.com/topics/626-data-export-no-longer-working/
This inadvertently helps this feature request. Unfortunately I cannot perform exports of more than one month due to the large amounts of data being processed.
That works for me, since I have all the data in SQL Express. Now all I need to do is append, which is much better than replacing the table every month to run my pivot table spreadsheet to match my electric billing schedule.
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