1 SD Card, 2 Phones

[Krakkpyppe]

So I have a Galaxy S3 and S4 (Verizon), both with broken charging ports, so I routinely switch my SIM and SD between the 2 in order to externally charge the batteries. Why does Spotify on one phone recognize my downloaded music while the other doesn't? And if I try to download it on the other phone, it will no longer appear on the first. Each time it downloads, it's taking up all of that space on my SD again. Is there a workaround here or am I just SOL on offline music? Any help would be greatly appreciated.

[Daniel]

Spotify cache is encrypted and will only work with the device/app that the cache was created with. If swapping the SD to a different phone then the encryption key is different and so the cache cannot be decrypted to play in the second device