Well, most portable electronics will us Direct Current energy, or DC energy, for short. Direct Current is a weaker form of electricity. Alternating Current is the other form of electricity. It is used in houses. The reason they don't use AC energy for small things is because the converter needed for the AC weighs about 2 pounds for a single appliance. To use one that can do multiple things at once, like the ones in your house, then you must buy the regular, larger converters, which cost around 2000 dollars for the cheaper ones. And, don't forget that they weigh about 3300 pounds each!
The popular energy of flashlight are Rechargeable Li-on battery, Alkaline battery.
Battery electric energy is converted to light energy of flashlight.
Potential energy
potential energy
A battery is the electrochemical cell is used as an energy source in a flashlight.
flashlight: the battery in the flashlight transforms it's chemical stored Energy into electrical Energy which is then transformed into radiant energy because of the light the flashlight gives off.
The flashlight can not be turned on as it no power now.
electrical energy
You cannot turn on a flashlight without battery inside. That's impossible if the only energy of flashlight is a battery.
in battery it is chemical energy, from the line, it is electrical energy, through the emitter, it is the light energy.
A flashlight may not light if there is no energy source or in this case battery.
The conversion is from chemical energy to electricity to light energy.