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This uses two green, two yellow, and one red LED to indicate the charge level of a 3.7V lithium battery.
This circuit uses a LM339N to activate a sequence of LEDS in order to display the charge of a 3.7V lithium battery. The extra resistor (RTP) is for the Charge controller to be connected. It's labeled RTP because I used a TP4056 in my tested circuit. The other two resistors that are separate from the other components are there to support a solar panel. If you desire to add one in your project, the IN terminals on your charge controller will connect to R13 and the solar panels will connect to R14. Other than that, don't forget to add a switch to your battery so that you can turn it on/off.