Lore wise, how long do Energy Swords and Gravity Hammers last?

I’m curious if any body knows how long said weapons actually last for. I mean, a sword that you can only use to slash someone ten times has to be a game mechanic thing, otherwise its a pretty piss poor weapon…right?

Lore-wise, they last significantly longer, without a hard-set on the number of uses (much like the Lightsabers of Star Wars).

Also, if they need re-charged, that can likely be done through the same plasma batteries they use to charge their other weapons.