Intro and warning

I put here my own personal mod for potions durations, there are some other similar mods out there, but I was not entirely satisfied of what they did. If my personal tweaks don't satisfy you, you can check those other mods.
This is a convenience mod, made to ease some tasks in the game (like tempering/enchanting, shopping...) and avoid to drink the same potion before every fight in a dungeon. This is not intended as a GodMode tool.
Only the duration of beneficial effects of potions gave been increased. No poison or enchanted object have been mistreated in the making of this mod.

Now a bit technical part for you to understand issues my mod can cause. In order to increase the duration of some potions, I have increased the duration of the effects directly in the Ingredients. Usually, that lead to increased gold value of each modified ingredient (and therefore of potions crafted from those ingredients). The problem is that it will break the balance of crafting potions : the potions with longer durations would have an enormous gold value, and as experience gained from crafting potions is related to their gold cost, it would greatly facilitates Alchemy levelling. And I did not want to unbalance the game.
To avoid that, I also modified the Base Cost of the Magic Effects which are used in the Ingredients I modified. The new Base Cost has been calculated precisely to compensate the extended duration impact on the gold value.  So ingredients and potions gold value and experience gain are not affected by my changes. (There is some exceptions to that : some ingredients already have an extended duration. I took this into account, but the duration increase I made to those ingredients is not proportional to the duration increase of the basics ingredients, so the Base Cost modification is not proportional either. Gold value for those special ingredients and the potions crafted with them is then different from vanilla one, but not in an unbalanced way).
I also have changed the durations of the same effects in the potions already present in the game, so their cost do not vary from vanilla (with the exceptions of potions already having an increased effect duration, as explained above).

Because the modifications I made concerned directly the Ingredients, Potions and Magic Effects of the game, my mod will conflict with any other mod that changes anything on the Ingredients/Potions/Magic Effects I tweaked. That means that the mod that will be loaded last will cancel the changes made by the other(s) mod(s) to those specific Ingredients/Potions/Magic Effects. Almost all the Ingredients and alchemical Magic Effects had to be modified, therego you can't use another Alchemy mod that touches the Ingredients and Magic Effects. See below the sections about compatibility.


    Content

With my mod, you will see :
- Fortify Barter, Enchanting and Smithing increase from 30 seconds to 15 minutes
- Fortify Carry Weight increase from 5 minutes to 15 minutes
- Fortify Alteration, Conjuration, Destruction, Illusion, Restoration, Block, Heavy Armor, Light Armor, One-handed, Two-handed, Marksman, Sneak, Pickpocket increase from 1 minute to 10 minutes
- Fortify Lockpicking increase from 30 seconds to 5 minutes
- Regenerate Health, Stamina and Magicka increase from 5 minutes to 10 minutes
- Fortify Health, Stamina and Magicka increase from 1 minute to 5 minutes
- Resist Magic, Fire, Frost, Shock and Poison increase from 1 minute to 5 minutes

Some ingredients had already an increased duration for some effects, that duration have also been increased (so for some effects, you can craft potions with durations longer than those described here. That only concerns effects dealing with Health, Stamina or Magicka).

Also as a bonus, two ingredients that displayed a Fortify Barter Effect have seen it changed to Fortify Persuasion effect, with a duration of 5 minutes. So now you can craft Speechcraft potions !


   Compatibilty

Good news ! That mod is compatible with :
- Better Alchemy
- Upgrade Old Potions
- Tonics Heal Over Time
- Better Crafted Potions
- Adamant (but as Adamant have a perk that increases the potions durations, you will end up with reeeeaaaly extended duration for the effects I modified) 


   Uncompatibility

Bad news... That mod is not compatible with : 
- Increased Enchanting and Smithing Potion Duration (do the same with different duration and only for enchanting and smithing potions)
- Longer potions Smithing Barter Enchanting Carryweight (do the same with different duration and for less effects)
- Skill Controlled Potion Duration (different way to increase the potions duration)
- Healing Over Time and Longer Lasting Potions (already have increased duration; for simply healing over time see Tonics Heal Over Time)
- Better Potions and Poisons
- Powerful Potions and Poisons - Alchemy Overhaul
- Awesome Potions
- Complete Alchemy and Cooking Overhaul


    Installation

/!\ That mod is opted for v1.6.640. However, there are no scripts in it, no SKSE requirement, it could very well be compatible with previous versions of the game. According to a SSEEdit check with a downgraded Skyrim back to v1.5.97, it should also work with that version (but tell me if it don't).
Dawnguard, Heartfire and Dragonborn required.

All you need is provided in the FOMOD. All the plugins are esl-flagged esp.
Download the FOMOD with a mod manager and check the files you want to install. There are patches for Unofficial Skyrim Special Edition Patch (v4.2.9a, but should work with v4.2.5b), and for Creation Club content (base plugin does not include Rare Curios, Fishing or Saints & Seducers).

Note that the potions that belong to the base game will update their effects durations as soon as the mod is enabled, but for crafted potions you have to craft new potions in order to see the increased duration. Duration changes does not apply to potions crafted before using this mod.

Installation manuelle : 
- Place "Potions Durations Tweaks.esp" into Skyrim Special Edition\Data.
- If you need a patch : place in the same folder the file(s) "PDT-xxxxx.esp", where "xxxxx" is the name of the patched content. "CC" stands for Creation Club. 

Update : remove the previous version before installing the newest. Savegame compatible.

Uninstall : Just uninstall the mod. The durations will return to their vanilla values, except for the potions you crafted while this mod was installed which will remain unaffected.


    Credits 

Bit of thanks to the makers of the tools I've been able to use, Creation Kit, SSEEdit, Unofficial Skyrim Special Edition Downgrade Patcher, and also to the Unofficial Skyrim Special Edition Patch.