I had a few really old C cell batteries, the old zinc-carbon or LeClanche type. I tore off the metal jacket and then what was left of the zinc and dirty black powder, leaving the carbon rod, which is used as the positive electrode. I took two of them and held them with a pliers in the flame of the stove, to heat them up to a dull red and burn off any tar or paraffin. Then I connected them to the positive and negative alligator clips of my 3 amp power supply and tried to get them to light up when touched together.
I wasn’t very successful. I managed to get a few flashes from the contact, but I think the power supply didn’t have high enough current. I did manage to generate enough RF interference to cause the digital TV to stutter and black out for a second when the rods made contact.
When I was very young and learning about electronics, I did this using a filament transformer for the power source. The transformer was probably capable of delivering 10 amps or more of current when the arc was started, so it made quite a bit of light.
Historically the carbon arc was the first form of electric light. It came early in the 1800s when in 1808 Humphry Davy managed to get enough current from the battery to make an arc. This was shown in the Youtube video History of Electricity from the BBC.