I am getting a large refund on my taxes (which has $7,500 for EV purchase), but I also installed an EV charger. After inputting the information, it shows $0 credit. Why?

It is not showing up as a credit like the regular EV purchase is. I know I am getting a refund back, but shouldn't this bring down my taxable income more? Is it because I am doing the standard deduction and this is not in addition to that?