SN2PowerTweaks

Three sliders for the things that actually run out of power in Subnautica 2. A lightweight UE4SS Lua mod that lets you tune battery capacity, charger speed, and base power generation independently — all configurable in-game via SN2ModSettings.

No .pak overrides, no save-file modification, no permanent changes — slide a value to 1 and the mod is effectively off for that category.

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What it does

Slider	Default	Range	Effect
Battery Capacity Multiplier	2×	1–10×	Multiplies MaxEnergyLevel on every battery and power cell. Covers Basic Battery, Acid (Advanced) Battery, Power Cell, and Fusion Power Cell V2. Preserves current charge ratio — a half-full battery stays half-full at the new cap.
Charger Speed Multiplier	2×	1–10×	Multiplies ChargeRate on every Battery Terminal and Power Cell Terminal.
Power Generation Multiplier	2×	1–10×	Multiplies BasePowerGeneration on every power generator component — solar panels, thermal plants, bioreactors, and hydro turbines. Sunlight / temperature / fuel scaling still applies on top, so the multiplier is to your peak output.

Each multiplier has its own enable toggle. A debug-logging toggle is included for troubleshooting.

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Requirements

1. UE4SS for Subnautica 2 — Nexus / GitHub
2. SN2ModSettings — Nexus — provides the in-game slider UI. The mod will load without it, but you'll have no way to change the defaults short of editing enabled.txt.

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Installation

1. Make sure UE4SS is installed correctly: dwmapi.dll next to Subnautica2-Win64-Shipping.exe, and the ue4ss/ folder beside it.
2. Extract this archive so the SN2PowerTweaks/ folder lands inside:

   <game>\Subnautica2\Binaries\Win64\ue4ss\Mods\
   

   Final structure should look like:

   ue4ss\Mods\SN2PowerTweaks\
   ├── enabled.txt
   ├── README.md
   ├── LICENSE
   └── Scripts\
       ├── ConfigManager.lua
       └── main.lua
   

3. Important: open ue4ss\Mods\mods.txt and add this line anywhere:

   SN2PowerTweaks : 1
   

   This ensures the mod loads before SN2ModSettings, otherwise the SN2ModSettings UI won't see Power Tweaks until you restart the game a second time. (See Troubleshooting for the reasoning.)
4. Launch the game. Open Settings → Mods — you should see "Power Tweaks" in the list with three sliders.

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Configuration

In-game (recommended): open Settings → Mods → Power Tweaks, move the sliders, changes apply within ~1 second to every existing battery / charger / generator in your save.

Manual file edit: the live values live in ue4ss\Mods\SN2ModSettings\saved\SN2PowerTweaks.lua after you've touched the settings once. Edit while the game is closed if you prefer.

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Compatibility

• Other power mods (Better Batteries, Faster Chargers, PowerBoost 10x, etc.): technically they all target the same underlying properties. If you stack them, the effects multiply — e.g. Better Batteries x1.5 + Power Tweaks 2× = ~3× capacity. Stable, but easy to over-tune. Pick one approach.
• Save files: no save-file modifications. Uninstall the mod at any time and your save reverts cleanly — values snap back to vanilla on next load.
• Multiplayer / co-op: untested. Should be safe for the host, but joining players will likely see desync if they don't have the same multipliers.

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Troubleshooting

"Power Tweaks doesn't show up in Settings → Mods"

SN2ModSettings only scans its registrations/ folder once at startup. If SN2PowerTweaks loads after that scan, its registration file is written too late and the UI won't see it.

Fix: make sure SN2PowerTweaks : 1 is in ue4ss\Mods\mods.txt. Mods listed in mods.txt load before auto-discovered ones, so the registration file is on disk before SN2ModSettings scans.

Alternative quick fix: just restart the game once. The registration file persists between runs, so on the second launch SN2ModSettings will see it during its startup scan regardless of load order.

"Values don't seem to apply"

Toggle Enable Debug Logging on in the mod's settings, reproduce the issue, then check ue4ss\UE4SS.log for lines starting with [SN2PowerTweaks]. The mod logs every snapshot and apply. If nothing logs at all, the mod isn't running — check that enabled.txt exists in the mod folder.

"I uninstalled but my batteries still have the boosted capacity!"

The mod only modifies values in-memory while the game is running — it doesn't write anything to your save. Loading your save without the mod will restore vanilla values. If a battery still looks boosted, it's because UE4SS injected old values into that object before you removed the mod. Drop and re-pick the battery, or save-and-reload.

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How it works (technical)

Three target classes, identified from a UE4SS CXX header dump:

Class path	Property	Notes
/Script/UWEInventory.UWEItemType	TunableData map → MaxEnergyLevel / EnergyLevel tags	Battery capacity is stored in each item type's tunable-data map (the same data the Better Batteries .pak mod edits). Editing it means newly-crafted batteries — and the tools/vehicles they're loaded into — carry the boosted capacity. The four battery item types are looked up by path with StaticFindObject.
/Script/UWEPower.UWEPowerTerminal	ChargeRate (float)	Parent class of both Battery and Power Cell terminals.
/Script/UWEPower.UWEPowerGeneratorComponent	BasePowerGeneration (float)	Component attached to every generator (solar / thermal / bio / hydro). Updates are applied via the SetPowerGeneration() UFunction, which fires OnRep_BasePowerGeneration so UI elements update too.

For each target, the mod snapshots the vanilla base value on first sight, then enforces value = base × multiplier. Sliding the multiplier later always computes from the true vanilla baseline, so it never compounds.

Chargers and generators are caught at spawn via NotifyOnNewObject (100 ms delay so the game has finished initialising the object). Battery item types load lazily — they only enter memory when the game first references them — so a 1 Hz loop re-applies battery capacity every few seconds to catch each type as it loads, and also reacts immediately to slider changes.

Limitation: batteries already present in a save keep their original capacity — the value was baked into the instance when it was created. Newly-crafted batteries get the boost. (This is the trade-off of editing at runtime vs. a .pak mod that bakes the data before the save loads.)

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Credits

• UE4SS by the UE4SS team, ported for Subnautica 2 by the Subnautica2Modding group.
• SN2ModSettings by Just-Chaldea — provides the in-game slider UI.
• ConfigManager pattern adapted from Capacity & QuickBar Tweaks by iTestor. The pattern of writing a settings manifest into SN2ModSettings/registrations/ is theirs.
• Inspired by the existing power-tweak .pak mods (Better Batteries, Faster Chargers, PowerBoost 10x) — same targets, just driven by Lua so you get sliders.

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License

MIT — see LICENSE. Use it, fork it, ship modified versions, no need to ask.

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Changelog

1.0.2

• Battery capacity now actually works. In 1.0.0/1.0.1 it modified the runtime battery actor, which the game ignores for capacity — so there was no real effect. It now edits the battery's ItemType.TunableData (the true source, same data the Better Batteries .pak mod uses).
• Newly-crafted batteries and power cells carry the boosted capacity into tools and vehicles.
• Battery item types load lazily, so capacity is re-applied periodically to catch every type (Basic, Advanced, Power Cell, Fusion Power Cell) as it enters memory.
• Note: batteries already in your save keep their original capacity — craft fresh ones to get the boost.
• Charger and power-generation multipliers unchanged (they already worked).

1.0.1

• Added Nexus + GitHub metadata so SN2ModSettings shows "View on Nexus" / "View on GitHub" buttons next to the mod.
• No gameplay changes.

1.0.0

• Initial release.
• Battery capacity, charger speed, power generation multipliers (1–10× each).
• SN2ModSettings UI integration.
• Per-instance baseline snapshotting so slider changes never compound.