LED Indicators

There are three types of LED indicators indicating the operation status of different parts of the

module:

Reverse connection LED indicators: when the battery or solar panel are reverse connected at the

BAT IN or SOLAR IN, the corresponding orange LEDs REV BAT or REV SOLAR turn ON, informing

the user a reverse connection error.

Charge LED indicators: when using the USB IN to charge the battery, the CHG USB LED (red)

turns ON. If the battery is fully charged, the CHG USB LED turns OFF and the DONE LED (green)

turn ON.The DONE is only used to indicate whether the battery is fully charged or not with

USB IN and does not apply to SOALR IN. If no battery is connected, both LEDs turn ON. When

using the SOLAR IN to charge the battery, CHG SOLAR (red) turn ON. This LED will be turned off

when the battery is fully charge, and flash when no battery is connected to BAT IN. If the sunlight is

too weak, the circuit may fail to charge the battery with solar panel. The CHG SOLAR turns OFF. It

should be noted that when changing the battery with SOLAR IN and discharging it on regulated

output OUT at the same time, CHG SOLAR will be ALWAYS ON, no matter the battery is fully

charged or not. Use the analog input to read whether the battery voltage is close to 4.2V to

determine whether the battery is fully charged under such situation.

Note: When the MPPT function is turned on or off, the CHG SOLAR solar charge indicator

will perform differently.

When the MPPT function is turned on, CHG SOLAR does not light up if the battery charge current 

is less than 250mA. Although the battery is still being charged with a small current, it means that 

the solar panel is under weak light, or it is not directly facing the sun. 

When the MPPT function is turned off, as long as the open circuit voltage of the solar panel is 

higher than 7V, the CHG SOLAR will be turned on, irrespective of charge current flowing into the 

battery.