It all depends on what credits your kids qualify you for. If they are all under the age of 17 at year end of the tax year, they each would qualify for $2000 of child tax credit which would be subtracted from your tax liability before the EV credit is applied. So you would need $13,500 of tax liability before credits. Your AGI for MFJ using the standard deduction would need to be $122,277 to have enough tax liability after the $6000 of child tax credits to leave $7500 of tax liability to offset the EV credit.
