It isn’t possible to download Chirp audiobooks to an external storage device, such as an SD card. The Chirp app and any related content will always be stored on your smartphone or tablet’s internal storage.
If you’d like to free up storage space on your device, we’d suggest deleting any downloaded books that you’re no longer listening to. You can learn how to do this by following the steps in this FAQ: How do I delete a book I’ve downloaded?
If we can be of any further assistance, please feel free to reach out — we’re happy to help! You can contact us here: Contact Us.