I added a hybrid inverter to ‘My Components’ but can’t add a battery to it in the inverter task.

If you are trying to use custom hybrid Inverter and battery components - you will need to make sure you have added the battery as its own component. This is true even for all-in-one systems. 

 You can do this under  Components > Edit Batteries . For more detailed instructions, take a look at our guide to setting up batteries in Easy PV .