Using 18650 batteries to power TV during power outage
@JRE's  advice is potentially true but also potentially fatal for the TV.
It may "just work". It's quite possible, as he says.
It MAY just smoke.
Probably not -  are you feeling lucky?

Also, 60V or more is potentially fatal for you.
60VDC CAN KILL - it is not worth playing with like this unless you are "suitably expert". You're not. Really. 

Safer is to build a 12V or 24V pack and obtain a commercial DC (12 OR 24v) to AC mains converter. Even building a converter yourself is FAR safer than a HV DC battery.    Switching DC at more than about 30 VDC is far more hazardous than is usually appreciated. At 48 VDC the actual voltage starts to get dangerous and above that - fatalities are easy.