In Borderlands 4, few resources are as valuable as SDU tokens, also known as Storage Deck Upgrades. These special tokens allow you to expand inventory space, unlock more backpack slots, increase bank storage, upgrade your Lost Loot system, and even expand ammo reserves. In short, if you're tired of running out of bullets or having to drop loot constantly, SDUs are your best friend.

As you explore the chaotic world of Kairos, you'll discover that SDUs are closely tied to character progression. The more tokens you collect, the smoother your journey becomes. While you can't buy SDU tokens directly, there are 11 reliable ways to earn them, spread across activities like exploration, boss fights, and hidden objectives. Here's the full guide to help you maximize your SDU farming.

1. Safehouses and Order Silos

One of the most consistent methods for gaining SDUs is unlocking Safehouses and Order Silos. These double as fast-travel points and reward you with 40 SDU tokens each when discovered.

·14 Safehouses = 560 tokens

·9 Silos = 360 tokens

That's 920 tokens total, making this one of the most efficient farming methods in Borderlands 4. Prioritize these early, since they also give you mobility advantages with fast travel.

2. Evocariums

The mysterious Evocariums are scattered across Kairos, usually in plain sight. Activating one triggers a small puzzle quest requiring you to locate a Golden Orb and place it back at the shrine. Doing so plays an audio log and rewards 15 SDU tokens.

·18 Evocariums total = 270 tokens

Evocariums are especially rewarding for lore enthusiasts, since they reveal story fragments alongside the SDU rewards.

3. Vault Symbols

Hidden across Kairos are Vault Symbols, iconic to the Borderlands franchise. Interacting with these symbols grants 5 SDU tokens each.

·46 Vault Symbols total = 230 tokens

Since Vault Symbols are small collectibles, they're a great way to supplement your SDU count during casual exploration.

4. Lost Capsules

While roaming Kairos, you'll occasionally stumble upon Lost Capsules. These must be delivered to the nearest Safehouse for credit. Each capsule nets you 15 tokens, with 20 total in the game.

·20 Capsules = 300 tokens

If you're thorough in your exploration, Lost Capsules can be one of the most rewarding side activities for SDUs.

5. Auger Shrines (Meditation Points)

Sometimes, taking a break from all the Psycho-slaying pays off. Auger Shrines, found mostly around Terminus Range, allow you to meditate. Each shrine interaction gives you 10 SDU tokens.

·10 Shrines total = 100 tokens

It's a smaller yield compared to other methods, but still worthwhile for completionists.

6. Propaganda Speakers

Propaganda towers scattered around Kairos can be hacked to silence enemy broadcasts. Each hacked Propaganda Speaker gives 20 tokens.

·27 Speakers total = 540 tokens

This activity not only grants SDUs but also clears up the world of enemy chatter, making the region more immersive.

7. Electi Safes

Across Carcadia Burn and the Dominion regions, you'll find Electi Safes containing valuable tokens. Each safe grants 10 SDUs, with 10 safes total.

·10 Safes total = 100 tokens

While not as abundant as other activities, Electi Safes are easy to find once you know their locations.

8. Order Bunker Bosses

Order Bunkers are mini-dungeons scattered throughout Kairos, each guarded by a boss. Defeating one grants 40 SDU tokens.

·6 Bunker Bosses = 240 tokens

Since these bosses also drop gear, this method is efficient for farming both loot and SDUs. If you're short on gear, this is also a great time to use Borderlands 4 Items to optimize your loadout before tackling them.

9. Auger Mine Bosses

Deep in the Abandoned Auger Mine, you'll find seven unique bosses. Each victory rewards you with 40 tokens.

·7 Bosses total = 280 tokens

This activity is combat-heavy but rewarding, perfect for players looking to stack SDUs while farming gear.

10. Ripper Drill Sites

The Ripper faction operates Drill Sites across Kairos. These encounters pit you against waves of enemies, but completing them earns you 40 SDU tokens per site.

·6 Drill Sites total = 240 tokens

Tackling these also weakens the Rippers' presence, giving you narrative and gameplay benefits.

11. Ancient Crawlers

The massive, derelict Ancient Crawlers once served as mobile faction bases. Now abandoned, they hide some of the most lucrative SDU rewards. Each crawler conquered provides 40 tokens.

·10 Crawlers total = 400 tokens

These are dangerous areas, but the payout is massive-worth prioritizing if you're hunting SDUs efficiently.

Total SDU Token Count

If you're diligent, you can collect approximately 3,620 SDU tokens across all activities. This is more than enough to fully upgrade your Vault Hunter's storage systems, ammo reserves, and loot recovery capacity.

Final Tips for Farming SDU Tokens

·Balance exploration and combat - Safehouses, Vault Symbols, and Evocariums can be collected while naturally progressing through missions.

·Focus on bosses for bulk tokens - Order Bunker and Auger Mine bosses offer large chunks of tokens alongside loot drops.

·Don't ignore Propaganda Speakers - While time-consuming, these provide one of the highest SDU totals in the game.

·Plan your farming route - Combining capsule collection, shrine interaction, and safehouse unlocks saves time.

Conclusion

In Borderlands 4, SDU tokens are the backbone of progression. Whether you're aiming for bigger ammo pools, a larger backpack, or a more forgiving Lost Loot system, these tokens will make your Vault Hunter far more efficient on the hostile world of Kairos. By using the 11 methods above, you'll steadily increase your SDU count while also uncovering lore, defeating bosses, and dismantling faction strongholds.

Collect enough tokens, and you'll never have to stress about ammo shortages or storage space again-freeing you to focus on what Borderlands 4 does best: chaotic, loot-filled mayhem. And if you want an even bigger edge, you can always buy Borderlands 4 Items or Borderlands 4 Money from eld.gg to supercharge your journey.