Cable Guide
How to Choose the Right Cable — Without the Guesswork
The cable you choose matters as much as the component you connect. Get it right the first time — and grab our free sizing guide to keep.
5-page A4 quick reference — print it, pin it in the shed. Or shop the genuine Tycab range →
The cable matters as much as the component
When it comes to automotive wiring, the cable you choose can be just as important as the components you’re connecting. You wouldn’t fill your engine with the wrong grade of oil and expect it to perform at its best — the same applies to your vehicle’s electrical system.
Cable that’s too small can cause excessive voltage drop, poor performance, overheating and, in extreme cases, a safety risk. Even the highest-quality batteries, brake controllers, DC-DC chargers, inverters and accessories can’t perform as designed if they’re fed through undersized cable.
The right cable doesn’t just carry power — it delivers performance.
Grab the Free Cable Selection Guide
We’ve put the whole thing into one handy guide. Match your project to the right cable, size an unmarked cable with the gauge guide, and shop the range in a couple of taps.
- Quick "I'm wiring…" picker — find your job, get the cable
- Full sizing tables — single, twin, multi-core and B&S battery
- Amp ratings & mm² for every common size
- Printable gauge guide — size an unmarked cable at 100% scale
- Genuine Australian-made Tycab throughout
No jargon. Print at 100% (not “fit to page”) so the gauge guide reads true.
Not sure? Call ( 03) 9879-1412 — we’ll pick it for you.
Quick Pick — "I'm wiring…"
Find your job, get a recommended starting point, then jump straight to stock. A guide only — the right size also depends on current draw, cable length and voltage drop.
| I’m wiring… | Recommended starting point | |
|---|---|---|
| Driving or work lights | 4mm Single Core or 2 x 3mm Twin Core | |
| UHF radio or accessories | 3mm or 4mm Single Core | |
| Dual battery system | 8 B&S or 6 B&S Battery Cable | |
| DC-DC charger | 6 B&S Battery Cable or 2 x 6 B&S Twin Core | |
| Caravan battery charging | 2 x 6 B&S Twin Core | |
| Electric trailer brake controller | 6mm Single Core or suitable Multi-Core | |
| Anderson plug installation | 8 B&S or 6 B&S Battery Cable | |
| Portable fridge | 2 x 4mm or 2 x 5mm Twin Core | |
| Solar panel wiring | 2 x 4mm or 2 x 6mm Twin Core | |
| Inverter (up to ~1000W) | 2 B&S or larger (depending on cable length) | |
| Large inverter (2000W+) | 00 B&S or 000 B&S (short runs) | |
| Winch | 2 B&S, 1 B&S or larger (manufacturer’s rec.) |
The Four Cable Types — What Each One's For
Single Core
One conductor. Lights, relays, gauges, UHF, accessories and power feeds — 3mm to 6mm.
Twin Core
Two conductors sheathed together — positive and negative to one accessory. Fridges, solar, chargers, Anderson runs.
Multi-Core
Three to seven cores in one sheath — for trailer lighting, brake controllers and caravan wiring in a single run.
Battery (B&S)
Heavy-duty, high-current. Starters, winches, inverters, dual batteries — 8 B&S right up to 000 B&S.
Single Core Automotive Cable
| Cable Size | Area mm² | Amp Rating | Typical Common Uses | Recommended Applications |
|---|---|---|---|---|
| 3mm | 1.13 | 20 | Relays, gauges, LED lighting, trigger wires | Lighting • Control wiring |
| 4mm | 1.84 | 28 | Driving lights, reverse lights, work lights | Lighting • Accessories |
| 5mm | 2.90 | 37 | Compressors, charging circuits | Accessories • Power feeds |
| 6mm | 4.59 | 48 | Brake controllers, power distribution | Brake controllers • Heavy accessories |
Twin Core Automotive Cable
| Cable Size | Area mm² (ea) | Amp Rating | Typical Common Uses | Recommended Applications |
|---|---|---|---|---|
| 2 x 2mm | 0.56 | 8 | LED lighting, pumps | Lighting • Camping |
| 2 x 3mm | 1.13 | 16 | Driving lights, UHF | 4WD accessories |
| 2 x 4mm | 1.84 | 22 | Fridges, solar | Camping • DC charging |
| 2 x 5mm | 2.90 | 29 | Large fridges, caravan accessories | Caravan power |
| 2 x 6mm | 4.59 | 38 | Anderson plugs, inverters | Caravan charging |
| 2 x 8 B&S | 7.71 | 59 | Trailer charging, brake controllers | Trailers • Dual batteries |
| 2 x 6 B&S | 13.5 | 82 | Lithium, DC-DC chargers | High-performance charging |
| 2 x 2 B&S | 32.07 | 150 | Winches, large inverters | Extreme current |
Multi-Core Automotive Cable
| Cable Size | Area mm² (ea) | Amp Rating | Typical Common Uses | Recommended Applications |
|---|---|---|---|---|
| 3 x 3mm | 1.13 | 14 | Trailer wiring | Brake controllers |
| 3 x 4mm | 0.92 | 12 | Electric brakes | Caravans |
| 5 x 2mm | 0.56 | 7 | Trailer lighting | General trailers |
| 5 x 3mm | 1.13 | 11 | Brake controllers | Trailers |
| 5 x 4mm | 1.84 | 15 | Heavy-duty trailer wiring | Commercial trailers |
| 7 x 2mm | 0.56 | 5 | Standard trailer wiring | Box trailers |
| 7 x 3mm | 1.13 | 10 | Trailer + auxiliary | Caravans |
| 7 x 4mm | 1.84 | 14 | Heavy-duty caravans | Commercial |
Amp rating is per core. For trailer installs, confirm pin/connector compatibility with your towing vehicle.
Battery Cable (B&S)
| Cable Size | Area mm² | Amp Rating | Typical Common Uses | Recommended Applications |
|---|---|---|---|---|
| 8 B&S | 7.71 | 74 | Dual batteries, Anderson plugs | Brake controllers • Caravan charging |
| 6 B&S | 13.5 | 103 | Lithium charging, DC-DC chargers | 4WDs • Caravans |
| 4 B&S | 20.26 | 135 | Battery interconnects, inverters | Power distribution |
| 3 B&S | 26.45 | 168 | Battery banks | High-current charging |
| 2 B&S | 32.07 | 188 | Winches, large inverters | Off-road • Commercial |
| 1 B&S | 39.55 | 210 | Large winches | Heavy battery connections |
| 0 B&S | 49.00 | 246 | Starter motors | Battery-to-battery links |
| 00 B&S | 64.15 | 292 | Large inverters (short runs), diesel starting | 4WD • Caravan • Industrial |
| 000 B&S | 83.19 | 335 | Very large inverters (short runs), trucks, marine | Industrial • Marine |
B&S (Brown & Sharpe / AWG) is the standard for heavy-duty battery cable in Australia. Use appropriate lugs, correct cable management and adequate fusing. When in doubt, go up a size — especially for longer runs.
Got an Unmarked Cable? Size It in 3 Steps
- 1. Identify the type. Single, twin, multi-core or battery cable — that tells you which table to use.
- 2. Match to the gauge guide. Print the guide at 100% on A4, then press a cleanly-cut cable end against the gauge shapes — the closest match is your size.
- 3. Still unsure? Calculate the area. Count strands x area of one strand. Example: 3mm auto cable = 14 strands x 0.32mm = 1.13 mm².
Print it right: the gauge guide only works at 100% scale on A4 — do not use “fit to page”. That’s why it lives in the downloadable PDF.
A Full Roll, or Just a Couple of Metres — We Cut to Length
Unlike a lot of suppliers, we’re happy to cut cable to the length you need — a full roll for the workshop or just a couple of metres to finish a weekend project. We stock one of the most comprehensive ranges of genuine Australian-made Tycab cable available: single and twin core through the full automotive range, right up to heavy-duty 6, 4, 2 B&S and Double 0 (00 B&S) battery and starter cable for winches, inverters and auxiliary battery systems.
From the Workshop
Nine times out of ten, it comes back to cable a size too small
“When someone’s chasing a mystery electrical gremlin — lights dimming, a charger not pulling its weight — it usually comes back to cable that was a size too small for the run. Sizing it right the first time costs a few dollars more and saves you the headache. If you’re not sure, ring us. We’d rather help you get it right than see you chasing voltage drop later.”
— Michael, HS Auto Parts
Cable Sizing — Common Questions
Choose the Right Cable. Get the Best Performance. Wire It Once, Wire It Right.
Not sure which cable is right? Call our team on (03) 9879-1412 — we’d rather help you get it right than have you chasing voltage drop later.
19,000+ auto parts sales • 99.7% positive feedback • family workshop since the 1970s • ships Australia-wide from Melbourne
Keep Reading
12V Cable for 4WD & Caravan
Choosing Tycab cable for a touring build — dual batteries, solar and camp power.
How to Select Cable Lugs
Got your cable sorted? Match it to the right lug for a safe, low-resistance termination.
Portable Brake Controllers
Wiring a brake controller? See the range and what suits your towing setup.
