Gas is what runs your fridge on the road, heats your water, and cooks your dinner when there’s no power in sight. Get the setup right and you’ll barely think about it. Get it wrong and you’ll be dealing with leaking fittings, a fridge that won’t stay cold, or a regulator that dies in the middle of the Kimberley. This guide covers the gas bottles, regulators, and fittings that actually hold up to full-time travel, plus what to look for before you spend a cent.
What Size Gas Bottle Do You Need?
Most Australian caravans run twin 9kg bottles on the A-frame at the front. That’s the default for good reason: a 9kg bottle is the standard swap size, so you can exchange an empty one at any servo, hardware store, or caravan park across the country. You’ll pay around $28 to $35 for a swap, or roughly $22 to $28 for a straight refill if you find a depot that does it.
How long a 9kg bottle lasts depends entirely on what you’re running. A three-way fridge left on gas full-time will chew through a bottle in around 10 to 14 days. Add a gas hot water system and a cooktop and you might get 7 to 10 days. If you’re only cooking and running a gas hot water service, a single 9kg bottle can stretch to three or four weeks.
Twin 9kg bottles with an auto-changeover regulator is the sweet spot for full-timers. You get roughly a month of buffer between refills and you’re never caught short in the middle of dinner.
A 4kg bottle is handy for a portable BBQ or a standalone camp cooker, but don’t rely on 4kg bottles as your main supply. Fewer places swap them and you’ll be refilling constantly.
Steel vs Composite Bottles
Steel bottles are the workhorse. They’re cheap (around $70 to $90 for a new 9kg), rugged, and every swap service in the country stocks them. The downsides are weight (a full 9kg steel bottle weighs about 16kg all up) and rust if you don’t look after them. On a coastal lap, steel bottles left exposed will start to surface-rust within a year or two.
Composite bottles (the translucent ones from brands like Viking and Kovea) are lighter by around 3kg per bottle, won’t rust, and let you see exactly how much gas is left. They cost more (around $150 to $190) and here’s the catch: you generally can’t swap them. You have to get them refilled, and not every depot will fill a composite bottle. On remote runs that becomes a real headache.
For most Big Lappers, steel wins on practicality. The swap network is unbeatable when you’re a long way from anywhere. Composite makes sense if weight on your A-frame is critical or you’re running a rig where every kilo counts.
| Type | Price (9kg) | Weight (full) | Swap or Refill? |
|---|---|---|---|
| Steel Most Practical | $70–$90 | ~16kg | Swap anywhere |
| Composite | $150–$190 | ~13kg | Refill only |
Gas bottles must be tested and re-stamped every 10 years. Check the date stamp on the collar before you buy or accept a swap. An out-of-test bottle can’t legally be refilled and no depot will fill it.
Regulators: What Actually Matters
The regulator drops the high pressure from the bottle down to the low, steady pressure your appliances need. In Australia that’s 2.75 kPa. A cheap, worn, or corroded regulator is the single most common cause of gas appliances misbehaving: a fridge that won’t get cold, a stove with weak flames, a hot water heater that keeps cutting out.
Auto-Changeover Regulators
This is the upgrade worth making. An auto-changeover regulator connects to both bottles at once and automatically switches to the second bottle when the first runs empty. A little indicator turns from green to red so you know it’s time to refill the empty one. You never lose gas mid-cook and you never have to crawl out at 6am to swap bottles by hand. For a twin-bottle caravan, this is the setup we’d fit every time.
Single-Stage vs Two-Stage
For a caravan, a single well-made regulator does the job. Where people get caught out is age. Regulators have a service life of around 10 years, and the diaphragm inside degrades whether you use it or not. If your van came with a regulator and you don’t know how old it is, replace it. It’s a $60 to $150 part that prevents a long list of frustrating faults.
Fit a small rubber cap over the regulator vent or mount it under a cover. Mud wasps love building nests in the vent hole, and a blocked vent will stop the regulator working properly.
Fittings, Hoses & Accessories
The bits between the bottle and the appliance matter more than most people think. Australian gas fittings use a left-hand thread POL connection or, on newer setups, an ACME quick-connect. Get the wrong fitting and it simply won’t connect, or worse, it’ll connect but leak.
Pigtail hoses (the short hoses linking bottles to the regulator) perish over time, especially in UV and heat. Cracked, hard, or sticky hoses need replacing. Budget around $25 to $45 per pigtail. Always buy Australian-certified hoses with the AGA approval mark, not cheap imports of unknown spec.
Other fittings worth having on hand: a POL to bayonet adaptor if you want to run a portable BBQ off your main bottle, a spanner sized for POL fittings, and a spray bottle of soapy water for leak testing.
~$70
What to Look For Before You Buy
- Test date: Check the collar stamp. Bottles need re-testing every 10 years or they’re useless for refilling.
- AGA approval: Every regulator, hose, and fitting should carry the Australian Gas Association approval mark. Don’t buy uncertified gear.
- Correct pressure: Regulators must be set to 2.75 kPa for Australian appliances. Imported units may be a different spec.
- Auto-changeover for twin bottles: Worth the extra $50 to $80 over a basic single regulator.
- Fitting type: Confirm whether your system uses POL or ACME connections before ordering anything.
- Vent protection: Choose a regulator you can mount under a cover or fit with a wasp-proof cap.
Our Top Picks
✔ Pros
- Swaps at any servo or hardware store
- Cheapest option upfront
- Tough and reliable
✗ Cons
- Heavy compared to composite
- Can surface-rust in coastal conditions
✔ Pros
- Automatic bottle switching
- Clear refill indicator
- Reliable, well-built unit
✗ Cons
- Dearer than a basic single regulator
- Needs professional fitting to certify
✔ Pros
- Around 3kg lighter than steel
- Won’t rust
- See-through level check
✗ Cons
- Refill only, not swap
- Roughly double the price of steel
Gas Safety & the Rules
Gas is safe when it’s installed and maintained properly, and a serious hazard when it isn’t. Any permanent gas installation in a caravan (regulator, fixed lines, appliance connections) must be done and certified by a licensed gas fitter. This isn’t optional. It affects your insurance and your registration.
Test for leaks whenever you connect a bottle or replace a fitting. Brush soapy water over every joint with the gas on and watch for bubbles. If it bubbles, turn the gas off and fix it before you go anywhere.
Turn your gas bottles off at the bottle valve before towing. It’s a legal requirement in most states and it’s the sensible thing to do. Running a gas fridge while driving is not worth the risk.
Fit a gas detector low in your van, near the floor, since LPG is heavier than air and pools down low. It’s cheap insurance for something you can’t smell in time while you sleep.
- Twin 9kg steel bottles are the best all-round choice thanks to the nationwide swap network.
- Fit an auto-changeover regulator so you never run dry mid-cook.
- Replace any regulator over 10 years old and perished pigtail hoses regardless of how they look.
- Only buy AGA-approved gear and have permanent installs done by a licensed gas fitter.
- Turn bottles off before towing and fit a low-mounted gas detector.
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