Here’s the practical fix: in Sub Cargo on Roblox, “underpower” usually means your sub or cargo system isn’t getting enough usable power, so you need to reduce load, improve power supply, or both. A Roblox performance guide also points out that lowering heavy systems and avoiding unnecessary strain can help a game run more smoothly.

What to check

  • Make sure the battery or generator is actually on and connected correctly.
  • Remove or pause anything draining power at the same time, such as extra lights, tools, or cargo-related devices.
  • If the game has an upgrade or power setting , raise output before adding more equipment.
  • Reconnect any loose wires or components if the sub has wiring you can inspect.

Fast fixes

  1. Turn off nonessential devices.
  2. Wait for the power source to recharge or stabilize.
  3. Move cargo one piece at a time instead of running everything at once.
  4. Restart the round or rejoin if the issue seems bugged.

If it keeps happening

  • Treat it like a load problem : too many things are drawing power at once.
  • Try using a simpler setup with fewer powered parts.
  • If you’re in a custom or modded sub, the design itself may be the problem, not your controls.

Quick note

A recent Sub Cargo Roblox tutorial mentions moving crates with rope back to the cargo collector, which suggests the loop may be more about steady transport than heavy power use. If your problem is that the cargo system stalls, the safest move is to simplify the route and keep powered actions minimal.

TL;DR: turn off extra power drains, check your battery/generator, reconnect anything loose, and move cargo in smaller steps.