What is it?

MPPT Solar Panel Controller with DC Converter rev.1.4c

• Complete Charge Controller for 1S Lithium-ion Battery
• DC Output Voltage: default 3.3V or 5.00 +0.25V
• MPPT Function: 6V 12V 16.2V 17.5V 18.2V
• Support Solar Panel 5W 10W 20W (you have to choose when buying)
• LB Low Battery status indicator falls to GND below 2.93V, HI is Vbat, LOW is GND
• PG Smart Power Good Output, HI is Vout-0.47V, output is open drain
• DC Output Current: 3.3V up to 3A or 5.00V up to 2.5A
• The product comes fully soldered/assembled.

Why did you make it?

• Designed for powering IoT solutions
• Low power consumption project
• Solar Power Bank
• Battery-Powered Equipment

What makes it special?

• Over-Charge / Over-Discharge/ Anti-Reverse/ Over-Temperature/ Over-Current protection Circuit,
• Automatic Conditioning of Deeply Discharged Batteries
• Automatic Recharge
• Charging Status Indication
• Solar panel charging efficiency: 77%~83%
• DC-DC High Efficiency: 96%
• DC-DC Automatic Transition Between Step Down and Boost Mode
• DC-DC Smart Power Good Output - PG output - The device has a built in power good function to indicate whether the output voltage is regulated properly. As soon as the average inductor current gets limited to a value below the current the voltage regulator demands for maintaining the output voltage the power good output gets low impedance. The output is open drain, so its logic function can be adjusted to any voltage level the connected logic is using, by connecting a pull up resistor to the supply voltage of the logic
• DC-DC Load Disconnect During Shutdown
• DC-DC Power Save mode Enable

• DC-DC Softstart and Short Circuit Protection - After being enabled, the device starts operating. The average current limit ramps up from an initial 400mA following the output voltage increasing. At an output voltage of about 1.2V, the current limit is at its nominal value. If the output voltage does not increase, the current limit will not increase. There is no timer implemented. Thus, the output voltage overshoot at startup, as well as the inrush current, is kept at a minimum. The device ramps up the output voltage in a controlled manner even if a large capacitor is connected at the output. When the output voltage does not increase above 1.2V, the device assumes a short circuit at the output, and keeps the current limit low to protect itself and the application. At a short on the output during operation, the current limit also is decreased accordingly.

• ShangHai Consonance Elec CN3791: "The CN3791 is a PWM switch-mode lithium ion battery charger controller that can be powered by photovoltaic cell with maximum power point tracking function with few external components. The CN3791 is specially designed for charging lithium ion batteries with constant current and constant voltage mode. In constant voltage mode, the regulation voltage can be fixed at 4.2V with ± 1% accuracy. The constant charge current is programmable with a single current sense resistor. Deeply discharged batteries are automatically trickle charged at 17.5% of the full-scale current until the cell voltage exceeds 66.5% of constant voltage. The charge cycle is terminated once the charge current drops to 16% of full-scale current, and a new charge cycle automatically restarts if the battery voltage falls below 95.5% of regulation voltage. CN3791 will automatically enter sleep mode when input voltage is lower than battery voltage. "

• Texas Instruments TPS63020: "The TPS6302x devices provide a power supply solution for products powered by battery. Output currents can go as high as 3A while using a single-cell Li-Ion. The buck-boost converter is based on a fixed frequency, pulse-width-modulation (PWM) controller using synchronous rectification to obtain maximum efficiency. At low load currents, the converter enters Power Save mode to maintain high efficiency over a wide load current range."