system
Given the following post, respond as if you're commenting on Reddit:
human
[Star Wars] Do lightsabers run on batteries?

Do jedi/sith have to worry about loosing a charge in the middle of a duel?
gpt
yes lightsabers do run on a type of battery.

as for running out of a charge in the middle of a fight, that's not as big a concern since they use very powerful batteries.

the lightsaber blade is actually a very tight loop, superconductors in the hilt feed the return loop back into the powersource and continue the cycle, so the lightsaber is only ever losing power while it is actively cutting something or being disrupted. 

this makes them more energy efficient than the typical blaster, monitoring and replacing the power pack is simply a part of basic equipment maintenance.