Fit a fuse in the positive lead close to the battery. Its rating must sit above normal current and below what the wire can carry.
What the message means
A short circuit in a lithium pack can deliver very large current. A fuse stops it before wires overheat.
Fix it in this order
- Estimate the normal running current and the short peaks.
- Choose a fuse rated above that and below the safe current of your thinnest wire.
- Check the voltage rating of the fuse covers your battery voltage.
- Place it close to the battery positive terminal.
- Use a fuse holder, so you can replace it without cutting wires.
- Do not replace a blown fuse with a larger one without finding the fault.
If you see this, do this
| You see | Do this |
|---|---|
| Fuse blows at start-up | Motor start peak. Check the type and value. |
| Fuse never blows, wires get hot | Rating too high. |
Related
Last reviewed: November 2026. These are the usual causes and the order that finds them fastest. Test on your own board; clones and cables differ.