How To Get The Max Inventory Space!

Always wondered how to achieve obtaining all of the backpack SDUs upgrades?
Well you have come to the right place, click on this guide and have the max inventory space in borderlands legitimately in no time!

Introduction

Things you must know before starting.

As you may find out you will need 3 of the DLCs, "The Zombie Island of Dr. Ned", "The Secret Armory of General Knoxx" and "Claptrap's New Robot Revolution". Since the other DLC "Mad Moxxi's Underdome Riot" has no claptrap rescue missions so it does not count towards collecting backpack SDUs. I really recommended buying the GOTY verson because it is much cheaper than buying all of it seperately and also in the sales it will only cost £4.99 for it.

Make sure when playing borderlands you can quit before saving. So first open up borderlands and start playing. Buy something of a vendor (something cheap). Soon after press ALT+F4 which closes the game immediately or press CTRL+ALT+DELETE then click on task manager and close borderlands. Wait a few seconds and then open up borderlands again. If it worked, the item you bought will not be there. You will use this method in acquiring some of the backpack SDUs in future.

Now I recommended you start a new character as you might of have messed up like me. If your new to the game, play as the siren since it is the easiest in my opinion to play and very helpful. She is very fast as she can use her action skill and speed for doing runs quickly, also she is very powerful as her primary weapon are SMGs and they are seen as the best for DPS in the game.

Playthrough 1

These claptrap rescue missions always involve finding a damaged claptrap then finding a repair kit and then going back to it for a chance to get a backpack SDU or grenade mod, XP and money. Sometimes the claptrap will even help you by locating a chest after turning in the mission.

Now when you first start playing you will be in playthrough 1. In this playthrough all the claptrap rescue missions you do will give a 100% guranteed backpack SDU as a reward except one.

There are technically 14 claptrap rescue missions in total (in each playthrough). Although the first one you do is part of the story but doesen't give you a backpack SDU as a reward.

The mission Claptrap Rescue: Lockdown Palace for some reason doesn't give you a 100% chance of getting a backpack SDU as a reward, instead sometimes it may give you a grenade mod. So by using the exit before saving method keep trying until you get it. By having a full backpack or even overloaded by mission rewards the chances of getting the backpack SDU seems to be higher but this still hasn't been proven properly so you don't have to do it. Make sure you don't walk near a save point after you get a grenade mod since the game will save and you won't be able to ever get that backpack SDU from that particular mission.

This is the list:

Mission names, locations and backpack SDU availability.
Claptrap Rescue in Fyrestone No
Claptrap Rescue: Safe House in Sledge's Safe House Yes
Claptrap Rescue: The Lost Cave in Lost Cave Yes
Claptrap Rescue: New Haven in New Haven Yes
Claptrap Rescue: Tetanus Warren in Tetanus Warren Yes
Claptrap Rescue: Scrapyard in Earl's Scrapyard Yes
Claptrap Rescue: Krom's Canyon in Krom's Canyon Yes
Claptrap Rescue: Trash Coast in Trash Coast Yes
Claptrap Rescue: Old Haven in Old Haven Yes
Claptrap Rescue: The Salt Flats in The Salt Flats Yes
Claptrap Rescue: Crimson Fastness in Crimson Fastness Yes
Claptrap Rescue: The Lumber Yard in The Lumber Yard Yes (DLC The Zombie Island of Dr. Ned required)
Claptrap Rescue: Lockdown Palace in Lockdown Palace Yes but not 100% chance (DLC The Secret Armory of General Knoxx required)
It's a Trap... Clap in Tartarus Station Yes (DLC Claptrap's New Robot Revolution required)

Playthrough 2

Now things are very different from playthrough 1 since only 7 (8 if you haven't done Claptrap Rescue: Lockdown Palace in the first playthrough) of the claptrap missions give you a chance of receiving a backpack SDU or a grenade mod (that we don't want).

First thing you must not do is complete the base game story in playthrough 2 (killing the destroyer), as this will give you a 0% chance of obtaining a backpack SDU or even a grenade mod in Claptrap Rescue: The Lumber Yard and It's a Trap... Clap. Make sure you do these two missions before doing Destroy The Destroyer as I made the same mistake!

This is the list:

Mission names, locations and backpack SDU availability.
Claptrap Rescue in Fyrestone No
Claptrap Rescue: Safe House in Sledge's Safe House Yes but not 100% chance
Claptrap Rescue: The Lost Cave in Lost Cave Yes but not 100% chance
Claptrap Rescue: New Haven in New Haven Yes but not 100% chance
Claptrap Rescue: Tetanus Warren in Tetanus Warren Yes but not 100% chance
Claptrap Rescue: Scrapyard in Earl's Scrapyard Yes but not 100% chance
Claptrap Rescue: Krom's Canyon in Krom's Canyon No
Claptrap Rescue: Trash Coast in Trash Coast No
Claptrap Rescue: Old Haven in Old Haven No
Claptrap Rescue: The Salt Flats in The Salt Flats No
Claptrap Rescue: Crimson Fastness in Crimson Fastness No
Claptrap Rescue: The Lumber Yard in The Lumber Yard Yes only if playthrough 2 story is not completed (DLC The Zombie Island of Dr. Ned required)
Claptrap Rescue: Lockdown Palace in Lockdown Palace Yes if not completed on playthrough 1 but No if already done on playthrough 1 (DLC The Secret Armory of General Knoxx)
It's a Trap... Clap in Tartarus Station Yes only if playthrough 2 story is not completed (DLC Claptrap's New Robot Revolution required)

If you did make the mistake of completing the story in playthrough 2 the only way of definitely getting the backpack SDU from those 2 missions is to go on a friends hosted game in which they did not complete the main story on playthrough 2.

Evaluation

Thank you dattebayo for the screenshot.

The legit max inventory space is 72.
An inventory of 42 spaces unlocks an achievement called "Fully Loaded".
Each backpack SDU gives 3 additional spaces to the inventory.
With more space you can have a larger collection of your weapons you would like to keep. With the bank from "Mad Moxxi's Underdome Riot" the total is 114. With the weapon, shield class mod and grenade mod slots this brings this up to 121.

If you have any questions, simply comment below.
What would be very helpful is if anyone can spot any spelling, punctuation and grammar for me to fix.

Hopes this helps and enjoy playing one of the best games ever!

[ChubbyMaN]

man screw you, you cant get sdu in lockdown palace on pt2 even if you didnt get one in pt1

[Shakon_Krogen]

so what i'm understanding is... that i need to use a third party program in order to get my slots up to 72? i'm currently capped at 45 and got nothing but grenade mods from every single CL4P-TP rescue

[Polaris]

I just tested the "Kill Rakk Hive, lose SDU at Tartarus Station" theory and I still got the SDU post-Rakk Hive.

Made a backup of a Siren, killed RH, Phase-Walked/ran through the objectives in the Robolution, got the repair kit for the Clap-Trap, and still got the SDU.

The loss of the SDU's availablity appears to be tied to entering The Vault; which scales all enemies in PT2 to +/-2 of player/host level. This makes more sense, since the RH doesn't affect the game-world, but the global level-adjust does.

I know this is a "necro" comment, but if someone else was worried about it, perhaps they'll see it and have that clarified instead of worrying over RH for nothing.

[Spamie]

I found a claptrap rescue mission in Krom’s Canyon in play through 2, would I have no chance in getting a backpack slot upgrade?

[Mr. Piggy]

+stephenjamesdude Dodge of the century. I was just about to kill Rakk Hive. You're my hero.

[stephenjamesdude]

Under no circumstance does part 2 or 2.5 lockdown palace reward a sdu regardless of the time or order you do them in, I have extensively tested all the methods listed here and other forums using a substantially overloaded inventory and only the default carrying capacity. The result was a 100% success rate on lockdown palace part 1 with 8 straight runs. Part 2 on the other hand wont yield no matter how you approach the claptrap turn in, which includes skipping part 1. Anyone claiming to have received one on part 2 is either deliberately misleading or simply has their playthroughs confused.

Also the point at which you lose the Lumber yard and tartarus station SDU on playthrough 2 is not triggered by killing the destroyer, its killing the Rakk Hive in trash coast that does it.

[ELECTRIC_CH3R7Y]

If anyone is having trouble in playthrough 2 try filling your inventory with healing kits. I got mine in the first 3 runs by doing that.

[Professor]

The drop rates on these are OUTRAGEOUSLY low. Who at Gearbox thought this was a good idea?

[Idle_Mind]

Woohoo I did it, all thanks to you and this guide!

[SpeedrunnerInTraining]

How do I get this without the friend?