connect a 5v 5w solar panel a usb port and a 3.7v 2.5A lipo with pcb. If I connect a phone to usb port it doesn't charge, but if I remove the battery from the circuit, it does. I suppose it's because battery pcb downgrade the voltage to 4.2v or there is not enough energy to serve both. There is a simple way to prioritize the usb or make them share? Thanks in advance for your help

PS Sorry to eventual mistakes but I'm still learning electronics.