This is awesome. One question, is there a point where one can tap in to 3.7v directly but is still protected by the low voltage cutoff?

What is the reason for 10 watt solar limit? I am currently using 6w 5v panels which cannot keep up on consecutive overcast/ limited sun days. If I keep the voltage below 6.5v can I connect higher wattage panels to increase the duration of charging (I understand it will be limited at max charge current of 900mA)? Thanks

2.4v drop out is quite low for a li-ion battery. I would expect more in the range of 2.75-3v. Is this configurable?

This solar module is specially designed for 3.7V Lipo (with a full charge cut-off voltage of 4.2V).
If your 18650 battery has the same charge cut-off voltage as the standard 3.7V Lipo, it is possible to connect multiple batteries in parallel.

And there is no limitation on the current of the solar panels, the solar manager will automatically regulate the current, so you don't need to care about the current parameter.

Can I only use a single cell 3.7V battery? Because I have connected three 3.7V batteries in parallel to have a 6600 mah. Is this the reason why it only have 4000 mah when charged?

You can remove the load on your output side before measuring the voltage, because if the ESP32 is consuming too much power, this could cause a voltage drop on the output side.

This product cannot detect the battery level of Lipo. If you need to check the power at the same time, you can use the Fuel Gauge at the same time.
The Fuel Gauge wiki also has an example of doing this.

https://www.dfrobot.com/pro...

Since LiFePO4 has a different charging cutoff voltage than LiPo, we do not recommend that you use LiFePO4 batteries.

Thanks for this. I have now doubled the solar panel current to 200mA. I am now able to charge the battery. However, it stops charging at 3.4V. It does not go upto 4.2V as indicated in the spec sheet.

Please advise on what I need to do to get the Li Ion cell upto 4.2V.

Regards,
Anand.

I have connected a 6V 100mA solar panel to the board. I have connected it to a 850mAh Li Ion cell.

The battery is discharging continuously even during full sunlight falling on the solar panel.

Over the last one week, a fully charged Li Ion cell has discharged from 3.7V to 2.7V.

Please could you advise on the issue?

Regards,
Anand Jhaveri

The USB port and the SOLAR IN port are internally connected in parallel. If the specifications of your solar panel are compatible with the specifications required by the Solar Power Manager, you can connect a solar panel with USB output to the Solar Power Manager.

You can use 3 18650 batteries in parallel, our specification means USB/Solar charging current is 900mA. it has nothing to do with the capacity of your batteries, if you have larger capacity, the charging will be slower, but the battery life will be longer.

My solar panel has a USB output. Does the "USB IN" connector on the DF0559 V1.1 implement the MPPT function the same as the "SOLAR IN" connector? Or should I breakout the USB from the panel into discrete wires and connect it to the 'SOLAR IN" connector. Just getting started with the integration and I have not yet verified if the panel has a regulated 5V output (Manufacturer simply states Max. voltage 5V).

Sorry we don't have the .f3d file for the Solar Power Manager.

Hi, I have a SG90 servo motor connected to my Arduino UNO board that runs on voltages ranging from 4.8V to 6V. If i connect a 3.7 V Li-ion battery to it and a 5V solar panel to the DFRobot Solar Power Manager 5V, will it be able to run the servo motor when connected to the Arduino?

No thanks!
Thank you for supporting DFRobot.

Hi,
I got a question for you. Is it possible to charge a LiFePO4 cell with the board?
Thanks for your answer in advance :)

Hi, Can it be used as a charging unit + BMS power management module for a portable device (tablet like) but instead of 5 volts from the solar power with a usb type C input?

I'm already developing an energy harvesting project on which I feed a battery using solar panels and Solar Power Manager 5V (DFR0559) to regulate the charge of the battery.

I've seen that this module uses an IC which implements a constant voltage MPPT algorithm to maximize the power given by the solar panel. My question is, how this algorithm exacly works? I mean, how does the module know which is the Vmp of the solar panel?

Thank you in advance

Please use the 5V solar pannel and charge the 3.7v Li battery.
This board is designed to work with components with such parameters.

What is the minimum current needed before the battery charges?