Solar lamp/phone charger output current too low for modern phones

Thread Starter


Joined Oct 24, 2022
I am building a solar lamp/phone charger following this page.

I have two 18650 batteries in parallel. The charger module is the usual TP4056 taking 5 V input, and limited to 1 A output. The voltage booster converts the ~3.7 V from the batteries to 5 V, but with a current limited to 600 mA (in practice even less than that).

The problem is that this current seems too low for recent phones, especially iPhones. I found another voltage booster outputting 5 V and 1-1.5 A. However, when I plug the phone in via USB cable, the phone starts charging for around 1 second (sometimes more) before the circuit shuts down. This seems to happen when the output current is more than 1 A. Perhaps this is due to the fact that the TP4056 charger module is limited to 1 A?

What would you do to get an output current to charge the phone close to 1 A or more? A phone would take around 1.4 A from a conventional electrical outlet. The constraint is that I need a charge regulator module such as the TP4056 to safely charge lithium batteries with a solar panel.

I've also heard iPhones might block such DIY charging?