Depends on the size of the kit. I have included a tea light or two in my hiking bag- typically good for a couple of hours. The long burn candles are also known as a plumber's candles. Check hardware stores- originally used for plumbers that were wiping lead joints on cast iron pipe. I also use them in the shop- lube saw blades, hand planes, etc.
Plumber's candles are short and fat (like some of us) and have a higher amount of stearic acid in the wax- slower burn.