So eh, you uh, want to make a contribution? Good... A-a sizable one, I hope.”— Mayor, The Precursor Legacy
Bring 90 orbs to the Mayor was a mission in The Precursor Legacy that Jak and Daxter completed to obtain a power cell. A common mission where the Mayor requested ninety orbs as a contribution to his re-election campaign in exchange for a power cell.
Upon owning a total of ninety Precursor orbs you can trade them with the Mayor for a power cell. The Mayor's hut is on the main rise in Sandover Village and is easily distinguishable by the windmill attached to the roof.