Shock Crystal Harvest

Background
You must collect 50 shock crystals from the "Lost Cave."

Walkthrough
You have to go into the cave, find the crystal stashes, shoot them, and then collect the ones that fall on the ground. There are five crystals per bunch. If you don't get five, shoot the bunch again.

This is really difficult if you're &lt;= level 13, unless you take advantage of the crystals respawning.

One tactic is to enter the cave, sprint to the first crystal stash, shoot it, collect it, then run for the cave exit. The next time you enter the cave, the crystal stash will have respawned and you can repeat. You get 5 crystals each time. If you click the left joystick, you can sprint. This method doesn't get you the Claptrap Backpak SDU upgrade, though.

The "Lost Cave" is also where you will encounter your first Claptrap repair quest that will reward you with an upgrade to your backpack storage space. This is techincally the second Claptrap repair quest, as the first one was in Fyrestone, but did not reward you with an upgrade to your backpack. As a reward, you will receive an SDU for your backpack gaining you three more inventory slots. Some people have reported getting another SDU on a second playthrough, but this does not happen every time and could be a bug.