An immense amount of technology, expertise, and information was lost in the Collapse in Arc Raiders, and the remaining humans living in Speranza are constantly trying to recover what they can. Even the smallest item can be useful and help prevent future issues and tragedies in the city.

Arc Raiders: Stable Housing Quest Walkthrough
Work those legs in pursuit of more information on housing projects.
The latest issue is a ceiling collapse that the city of Speranza is still reeling from, and one of the problems it left in its wake was a large-scale power outage. Celeste has some information on a battery prototype connected to Project Heartwood, and its lack of reliance on electricity would be a huge help if another power outage occurs, and they can successfully
Where To Find The Battery Prototype
For Worth Your Salt, Celeste asks you to head to Spaceport, and you’ll need to complete all the objectives in one round for them to count, but fortunately, they’re all going to be in the same location: Rocket Assembly.
The Rocket Assembly building is in the northeastern part of Spaceport, and as soon as you go inside, head for the bright red catwalks in the upper left-hand corner of the building. Look for a set of lockers in the corner of the catwalk, and you’ll find a white container on the ground next to them.
Rocket Assembly is a great place to find Exodus loot like Magnetic Accelerators and Exodus Modules, and the lockers at the back of the building often have at least one inside, especially with a map modifier that increases the loot.
Search it to find the hidden Battery Prototype, and like Fuel Cells and Field Crates, you’ll have to carry it in both hands, so you’ll want to make sure you’ve gotten rid of any Fireballs and Pop Rollers nearby so they don’t attack while you’re vulnerable.
How To Charge The Battery Prototype
Carefully drop to the floor, and bring the Battery Prototype to the red machinery just below, and you’ll find a white box with a control panel next to it, the Industrial Charger.
It’ll have a bright blue-highlighted section where you can put the Battery Prototype. Place it, then interact with the machine to start the process, and it’ll only take a few seconds to get charged up, which will complete the fourth objective.
The last thing you need to do is take the now Charged Battery to the drop-off point. Pick it up from the Industrial Charger, stay on the first floor, and carry it to the upper left-hand corner of the room, near one of the doors of the building.
You’ll find another white box on the ground near a set of metal supports and beams against the corrugated wall, and this one will be open. Interact with it once to place the battery inside, and now the final objective will be complete, so you can head back to Speranza.
Speak to Celeste to complete the quest, and as a reward, you get some EXP and the Vita Spray Blueprint, an incredibly handy healing item that works best when in a group, or when you’re doing Duos or Trios, as it can heal multiple raiders at one time.
Arc Raiders: A Dead End Quest Walkthrough
Behind the door lies information and loot in equal measure.