Check the TV manual and see if you can tell if the input is listed as 12v, or something like 12-15v. You can probably find a PDF of the manual on the manufacturer’s website. If it truly wants 12v specifically, you might consider a 12v DC to DC power supply that will take the 12-14v range that your charging system will produce and regulate it to 12v. I did this for my mobile Internet equipment. Something like this (you would need to make sure you get one rated for enough amps to power the TV.). https://www.amazon.com/Converter-Automatic-12V-Waterproof-Transformer/dp/B07WFMKMV9