What can I do when the battery doesn’t turn on?

Make sure the battery case still has enough power.

Push your iphone to the very bottom of the case, then  connect the top piece tightly, finally press the button for 3 seconds

1.When you want to charge the case only

Use the original apple lightning cable and wall adapter(5V/1A ONLY) ,don’t use high voltage or QuickCharge deployed adapters) and plug into the case,then press the button on the back to show the juice left and then star charging the case. 

2.When you want to charge the case and phone together

Please install your phone to the case ,make sure the top part close to the body tightly, use the original apple lightning cable and wall adapter(5V/1A ONLY) ,don’t use high voltage or QuickCharge deployed adapters) to charge,then press the button on the back to show the juice left and then star charging,In order to protect your battery of iPhone, it charges your phone to 100% first, then transfer to charger the battery case,it can’t charge the phone the case at the same time.

3.When you want to use the battery case to charge your phone

Please install your phone to the case ,make sure the top part close to the body tightly. ?Just press the button on the back of battery case 1s to show how much juice is left , one LED light means 25% power, keep it pressed for 4 seconds to start or stop charging.