The OTG cable only supports Android OS.

http://support.epsolarpv.com/support/solutions/articles/48000968524-does-the-app-support-otg-cable-in-ios- 


* Lithium battery is not supported as well


Required Materials: OTG Cable, CC-USB-RS485-150U Cable, Android Phone, Solar System.


Steps:

1. Download the application from EPEVER official website https://www.epsolarpv.com/downsoft.html 


2. Install the application to your phone


3. Power on the Solar System


4. Connect CC-USB-RS485-150U Cable to the OTG cable


5. Connect CC-USB-RS485-150U to the Solar Charge Controller


6. Connect OTG Cable to your Android Phone


7. Select EPEVER(SPP)


8. Open the EPEVER(SPP) application


9. Go to "Controller"


10. Go to "Device Settings"


11. Change "Communication Mode" to "Wired"


12. Click on "Read"


13. You are all set after it says "Operation Successful"