I have doubts with respect to choosing a converter for the solar charge controller

[Labet]

So I am designing a solar charge controller for a 30 W solar panel with following specifications:
Vmp=21.5V
Imp=1.71A
Voc=21.6V
Isc= 1.85A
I am planning to connect the controller to a 12V battery. So the question is do I need to use a buck converter or a buck boost converter and why?

 

[sunshine_eggo]

So I am designing a solar charge controller for a 30 W solar panel with following specifications:
Vmp=21.5V
Imp=1.71A
Voc=21.6V
Isc= 1.85A
I am planning to connect the controller to a 12V battery. So the question is do I need to use a buck converter or a buck boost converter and why?

Give up. If you have the ability to design a solar charge controller, you shouldn't have to ask the question.

 

[MisterSandals]

Here ya go, 12 bucks. I have 3 of these for little panels, very reliable and easy to use.

https://www.amazon.com/Controller-Intelligent-Regulator-Paremeter-Adjustable/dp/B08NFSCZ4V/

 

[Labet]

Give up. If you have the ability to design a solar charge controller, you shouldn't have to ask the question.

Lol let me try at least, that wouldn't harm anyone would it? In most of the videos related to designing of solar charge controllers on Youtube, I have noticed that they have used buck converters. So my question is why aren't they using a buck boost converter?

 

[MisterSandals]

So my question is why aren't they using a buck boost converter?

Probably because of cost and simplicity. In the old days when SCCs were mostlyPWM, panels were designed for specific battery voltages, about 6-8V above their corresponding battery charge voltage. So a buck converter was all that was needed.