The second lightsaber of Obi-Wan Kenobi was the lightsaber that Obi-Wan Kenobi, a Jedi Knight, built and used after his first one was lost in the battle on Naboo.
Obi-Wan Kenobi's second lightsaber, created as a replacement for his first lightsaber, used a kyber crystal to produce a blue plasma blade.
The Jedi Council tasked Kenobi with a mission to the planet Dallenor in the Mid Rim Territories. The purpose was to verify the discovery of a Jedi holocron by a team of archeologist. During this mission, Kenobi used his lightsaber to protect himself and his Padawan Anakin Skywalker from a band of pirates.
Around 29 BBY, Kenobi used this lightsaber during the mission to Carnelion IV.
Yoda, the Grand Master, was captured from Glee Anselm. In response, Kenobi and Skywalker started a rescue mission, unaware that it was actually a trial for the two Jedi.
In 22 BBY, Kenobi used the lightsaber during the Separatist Crisis. He severed the hand of Zam Wesell, a Clawdite bounty hunter who was hired to assassinate Padmé Amidala, the Senator from Naboo. This occurred in the Outlander Club, a nightclub in the underworld of Coruscant.
He also used this weapon in a skirmish against Jango Fett, a bounty hunter, on Kamino.
During his capture on Geonosis by Count Dooku, the Separatist leader, the Geonosians took the weapon. During the First Battle of Geonosis, Obi-Wan used a lightsaber provided by Sephjet Josall, a fellow Jedi Knight.
After being promoted to Jedi Master following the Battle of Geonosis, Kenobi constructed his third and final lightsaber.