Find the hidden power cell (Volcanic Crater) was a mission in The Precursor Legacy that Jak and Daxter completed to obtain a power cell. The mission entails a hidden power cell that Jak discovered in Volcanic Crater.
At the entrance of Spider Cave, turn around and look up to see a strong box high up lodged into the rocks. This is the one you will have to destroy to get the power cell. To destroy it you will need yellow eco which can only be found inside Spider Cave, flowing out of some of the vents in the first cavern.
Once you have made your way up to the many ledges on the cave walls (using web trampolines) you will have to look for a vent that is close to the cave entrance. Once you have done so and started channeling yellow eco, jump down (using spin kick to break your fall) and immediately start running out of the cave into Volcanic Crater. Once you are in view of the strong box use your goggles () to aim and shoot it down, releasing the cell inside.