Noun
tealight (plural tealights)
A small, typically circular candle encased in a thin metal cup, so that it liquefies completely when lit and burns as a wick immersed in molten wax.
Synonym: tea candle
Most dessert fondues require very little heat to keep the fondue in a liquid state, so a small tealight is the only source of fuel you need. Source: Internet
Place a tealight or battery tealight candle inside. Source: Internet