I am using arduino uno to make a solar charge controller where i use buck boost converter.
When i connect the solar panel which gives vout=18v ( at open circuit) suddenly drops to 6 to 7v when i connect it to the buck boost converter.. i donknow whats the problem.. help me to rectify this problem. i have attached a image of my circuit
The solar panel rating is (11w)
Vout=17v
Imax=0.67v
I want to charge a 12v battery charger so i need a output voltage of 13.8 v at the converter output.
The solar cell is unable to deliver enough current. You can probably just hook the solar cell to the battery thru a diode and not worry about it assuming it's 12V battery. Otherwise, you will need to connect multiple cells in parallel to deliver more current.
It looks for me as voltage inverting converter, why do you think you need one?
SPanel voltage already above your battery voltage, so you need step down switching regulator
I had a similar problem and after much stuffing around and head scratching, found that you need a capacitor (100-100uF) across the solar panel leads to stablise the buck converter. You still have to be careful to not overdraw on the current.
