Thanks for reading this post, I hope you can help me!
Lately I have been doing research for making my own solar powered phone charger with integrated powerbank. I am not extremely experienced with electronics so I would love to have some feedback on the circuit I came up with (image attached).
The idea is that I can charge my phone or my own powerbank (referred to as devices from now) with solar panels while I connect my devices via USB and when no device is connected, the generated power will be stored in a li-ion cell. Then I can later use this power to charge my devices.
Attached you can find the circuit that I came up with. I will explain it now. To start, there are two approx. 5V, 1A(max) solar panels in series to provide at least 5V at all times. This is connected to this XL6009 4A dc-dc converter to make it 5V. By switching a switch you can choose to get all the power to female usb output to charge devices at max power. Or... and this is the part I am not sure of yet... You can choose to power this TP4056 board in order to charge this li-ion battery. This then outputs 5V via this boost board to another female USB to charge from the powerbank.
I feel like what I want can be done in a better way and there might be mistakes I miss. Does it work as I intend it to work? What would you change?
And one major question I cannot find the answer to anywhere: With this charger board, is it possible/safe to drain the battery while charging it?
Lots of thanks in advance for taking time to read and hopefully help me with this!!!
The only question with an easy answer: And one major question I cannot find the answer to anywhere: With this charger board, is it possible/safe to drain the battery while charging it?
If you put a load on the battery/charger, the charger will supply all the current to the load it is designed to supply because it's voltage is higher. The battery will supply no current until the charger voltage is less than the battery voltage. Too much load will smoke the charger or pop it's circuit breaker. So, don't do it.
Paul
Not enough information.
two approx. 5V, 1A(max) solar panels in series to provide at least 5V at all times.
No solar panel will do that in the dark. What happens with the regulator and charge controller then?
Should I solve this issue by using a comparator circuit and relay/transistor to switch of the input voltage on the regulator when it goes below say 5V (can be lower because than it will boost i guess)
Solar panels dont behave properly if you feed them directly into switching type voltage regulators, as such regulators assume a voltage source to power them, and solar panels behave like a current source.
A better approach is to use the solar panels to directly charge a battery, and then use the battery to power what devices you need.
mauried:
Solar panels dont behave properly if you feed them directly into switching type voltage regulators, as such regulators assume a voltage source to power them, and solar panels behave like a current source.
A better approach is to use the solar panels to directly charge a battery, and then use the battery to power what devices you need.
Alright, thanks for that information!! In the case of not using the regulator, I will run into the issue that I can not charge my devices while the solars charge my battery as Paul_KD7HB pointed out. And the charger board has an input range of 4.5V-5.5V. What would be your setup suggestion?
Again thanks for your help!
