This Victron wire size chart gathers the fuse and cable sizes Victron prints in its own manuals into one page. Use it as a quick reference while you plan, but always check the manual for your exact model, since sizes change between versions. Victron’s general advice is simple: fuse every positive conductor, and size each cable for both its fuse and its run length.
Electrical work can be dangerous: follow the manual, fuse and size every cable correctly, and use a licensed electrician for anything connected to household wiring.
Why Voltage Changes Everything
Current equals watts divided by volts. A 2,400W load draws about 200A at 12V, 100A at 24V and 50A at 48V, before inverter losses. Double the voltage and you halve the current, so you can use smaller cable and smaller fuses. That’s why Victron’s 48V inverter/chargers use far thinner battery cable than the 12V versions.
Victron Wire Size Chart: MultiPlus-II 120V
| Model | Battery bank | DC fuse | Cable, 0–5m |
|---|---|---|---|
| 12/3000/120 | 400–1,200Ah | 400A | 2x AWG 1/0 |
| 24/3000/70 | 200–700Ah | 300A | AWG 1/0 |
| 48/3000/35 | 100–400Ah | 125A | AWG 1 |
| 24/5000/120 | 400–1,200Ah | 400A | 2x AWG 1/0 |
| 48/5000/70 | 200–800Ah | 200A | AWG 2/0 |
Source: Victron MultiPlus-II 120V manual, installation chapter. Longer runs need thicker cable (see the manual).
SmartSolar MPPT Battery Fuses
| Charger | Minimum fuse | Maximum fuse |
|---|---|---|
| MPPT 100/30 | 35A | 40A |
| MPPT 100/50 | 55A | 70A |
Source: Victron BlueSolar/SmartSolar MPPT 100/30 and 100/50 manual.
Victron says to use flexible, multi-stranded copper cable for the battery connection.
Orion XS 12/12-50A DC-DC Charger
| Item | Value |
|---|---|
| External fuse (both ends) | 60–70A |
| Cable, under 5m | 16mm² / 6AWG minimum |
| Cable, 5–10m | 4AWG (21.2mm²) minimum |
| Max terminal size | 4AWG |
Source: Victron Orion XS 12/12-50A manual, “Cable and fuse recommendations.”
Put one fuse near the starter battery and one near the house battery.
Fuse Types by System Voltage
| System | Lynx Distributor fuses |
|---|---|
| 12V or 24V | 36V-rated MEGA fuses |
| 48V | 58V-rated MEGA fuses |
Source: Victron Lynx Distributor manual.
Each Lynx module is rated 1000A. The total of all the fuses shouldn’t exceed the lowest-rated module in the chain.
Rules of Thumb From the Manuals
- Short and thick: keep battery cables short, and match the positive and negative lengths.
- Fuse near the source: put the fuse close to the battery.
- Torque matters: use the torque values in each manual, since loose lugs heat up.
- Use Wiring Unlimited: Victron’s free book covers voltage drop and cable sizing for long runs.
For the complete spec sheet and current manual, see the Victron MultiPlus-II page.
AWG to mm² Conversion
| AWG | Cross-section (mm²) | Nearest metric size |
|---|---|---|
| 8 | 8.4 | 10mm² |
| 6 | 13.3 | 16mm² |
| 4 | 21.2 | 25mm² |
| 2 | 33.6 | 35mm² |
| 1 | 42.4 | 50mm² |
| 1/0 | 53.5 | 50–70mm² |
| 2/0 | 67.4 | 70mm² |
| 4/0 | 107.2 | 95–120mm² |
Victron’s manuals mostly list both sizes. When converting, round up to the next standard metric size, never down.
Quick Current Table
| Load | 12V | 24V | 48V |
|---|---|---|---|
| 500W | About 42A | About 21A | About 10A |
| 1,000W | About 83A | About 42A | About 21A |
| 2,000W | About 167A | About 83A | About 42A |
| 3,000W | About 250A | About 125A | About 63A |
Estimates: watts ÷ volts, before inverter losses. Add 10–15% for inverter efficiency and size for the inverter’s maximum, not your average load.
How Voltage Drop Works
Voltage drop grows with current and cable length. In a 12V system, losing even 0.5V means about 4% of the voltage is gone before it reaches the load. Victron’s Wiring Unlimited book suggests keeping voltage drop low, and its tables show how thick a cable needs to be for a given current and length. A simple estimate:
Voltage drop ≈ current × total loop length × copper resistance ÷ cable cross-section
Copper resistance is about 0.0175 ohm·mm²/m. For 100A over a 4m loop (2m each way) on 35mm², that’s roughly 0.2V (estimate).
Common Fuse Types
| Fuse type | Typical use |
|---|---|
| MEGA | Lynx Distributor and battery outputs |
| MIDI | Smaller DC circuits, chargers and MPPTs |
| ANL | Inverter and battery feeds |
| Class T | Main battery fuse, especially lithium, for its high interrupt rating |
| Blade (ATC/ATO) | Low-current DC loads such as lights and pumps |
Always check the fuse’s voltage rating against the system voltage, especially at 48V.
Worked Example: A Van With a MultiPlus-II 12/3000
- Battery bank: 400Ah lithium, inside the manual’s 400–1,200Ah range.
- DC fuse: 400A, per the manual’s table.
- Battery cable: 2x AWG 1/0 for a run up to 5m.
- MPPT 100/50: 55–70A fuse, with cable sized to that fuse.
- Orion XS 12/12-50A: 60–70A fuses at both ends, 6AWG minimum for runs under 5m.
Follow the manual for each device; these are the same figures as in the tables above, pulled together for one build.
Worked Example: A 48V Cabin With a MultiPlus-II 48/5000
- Battery bank: 400Ah at 48V, inside the manual’s 200–800Ah range.
- DC fuse: 200A, per the manual’s table.
- Battery cable: AWG 2/0 for runs up to 5m.
- Lynx Distributor: 58V-rated MEGA fuses for every output.
Compare that with the 12/3000 van above: the cabin inverter handles more power on half the fuse rating and a single cable.
Planning Checklist
- List every device and its maximum current.
- Pick each fuse from the device’s manual.
- Size each cable for its fuse and its run length.
- Keep battery cables short, and match positive and negative.
- Check every fuse’s voltage rating against the system voltage.
FAQ
What gauge wire for a Victron MPPT 100/30?
The manual sets a 35–40A battery fuse. Size the cable for that fuse and keep the run short.
Is 48V worth it for wiring alone?
For inverters of 3,000VA and up, it often is. A 48V system draws a quarter of the current of a 12V one.
Should I use tinned copper cable?
Tinned copper resists corrosion, which is why it’s popular on boats and in damp spaces. Whatever you choose, use flexible, multi-stranded copper as Victron recommends.
Do positive and negative cables need the same size?
Yes. The negative cable carries the same current, so size it like the positive and keep the lengths matched.
Sources: Victron MultiPlus-II 120V manual; SmartSolar MPPT 100/30 and 100/50 manual; Orion XS 12/12-50A manual; Lynx Distributor manual (victronenergy.com, accessed Oct 2026).
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