It happens to nearly every household eventually. The snags are half cooked, the guests have arrived, and the flame quietly fades to nothing. The bottle is empty, the servo is fifteen minutes away, and dinner moves indoors to a frying pan. Getting a BBQ gas bottle right — the size, when to swap, when to refill, and how to store it — is what keeps a Saturday on track.
This guide follows the life of the bottle rather than the barbecue: sizing, swapping, storage and safety. We do not sell LPG bottles themselves, but every gas BBQ in our BBQs and outdoor cooking range runs on them.
What size BBQ gas bottle do you need?
The 9 kg bottle is the standard Australian BBQ bottle. It is the size swap cages are built around, and the size most full-size cabinet BBQs are designed to carry. If you are buying a new BBQ, assume 9 kg unless the manual says otherwise.
Smaller bottles, commonly around 4 kg, suit portable and camping cooking where weight and boot space matter more than run time. The Napoleon Travel Q Pro with Scissor Legs Portable BBQ ($999) is built around exactly that: easy to lift, easy to stow, quick to swap over at a campground.
Big cabinets burn gas faster, so households cooking outside several nights a week usually keep a spare bottle rather than a bigger one. A five-burner such as the Napoleon Rogue XT 625 SIB 5 Burner BBQ with Infrared Side Burner ($2,999) rewards that habit. Larger 15 kg and 45 kg bottles exist, but they are generally for plumbed or commercial installations set up by a licensed gas fitter.
Before you upsize, measure the bottle bay. A bottle that fouls the shelf or blocks the cabinet's ventilation openings is not an option, whatever the price.
Swap or refill?
A swap is an exchange: you hand over an empty bottle at a cage or counter and walk out with a full one. Whatever bottle you receive is the operator's responsibility to keep in date and in good condition, so re-testing never becomes your problem.
A refill puts gas into your own bottle, weighed in by a trained operator. You pay for the gas that actually goes in, which usually works out cheaper per kilogram, and you keep a bottle whose history you know. The trade-offs are opening hours, and the fact that a bottle outside its stamped test date will be refused.
| Option | Best for | Watch out for |
|---|---|---|
| Swap cage | Weekend cooks who want a full bottle in two minutes | You lose your own bottle |
| Refill by weight | Regular cooks chasing the lowest cost per kilogram | Limited hours; bottle must be in test date |
| A second spare | Households cooking outside several nights a week | Needs safe outdoor storage |
Either way, the habit worth building is not running to empty on purpose. Swap or refill when the bottle feels light, not when the flame dies mid-cook.
What the stamps on the collar tell you
Every LPG bottle carries stamped markings on its collar, and they matter more than the paint. One of them is a test date, which sets when the bottle must be re-tested or taken out of service. Refill operators check it before they fill, so read it yourself when you buy or inherit a bottle.
Test periods are set by Australian standards and by the bottle's own markings, so confirm the schedule with your gas supplier rather than guessing, and treat an unreadable stamp as out of service. The collar also carries the tare weight, the empty weight a filling operator works to so a bottle is never overfilled.
Condition is the other half of the check. Deep rust, dents, gouges, a damaged foot ring or a valve that will not turn smoothly all mean the bottle goes back to a supplier. Do not refill it, do not paint over corrosion, and never put it in a kerbside bin.
Where the bottle sits matters too. Cabinet BBQs such as the Coleman Revolution 4 Burner BBQ with Side Burner - Shadow Gloss ($1,749) house the bottle in a ventilated bay. Those vents exist because LPG is heavier than air and sinks, so keep them clear and store nothing else in the bay.
Storing and transporting a bottle safely
Three rules cover most of it: upright, outdoors, secured. LPG bottles are designed to stand vertically so the valve draws vapour rather than liquid, and laying one on its side is a genuine hazard rather than a shortcut.
Store bottles outside in a well-ventilated spot, away from drains, pits and anything that could ignite. Never keep one indoors, in a closed garage, under the house or in a cupboard. Turn the valve off firmly whenever the BBQ is not in use, even if you believe the bottle is empty.
Transport upright and restrained. Stand the bottle in a milk crate or wedge it so it cannot roll, keep a window down, and drive straight home. Leaving a bottle in a hot, closed boot for hours on a summer day is exactly the situation to avoid, because heat raises the pressure inside.
Whenever you reconnect, brush soapy water over the valve, regulator, hose and BBQ connection with the gas on and every burner off, then watch for bubbles. Never test with a flame. Our weekend BBQ deep-clean plan covers that leak test alongside the annual burner and hose service, and a cover from our BBQ accessories range keeps rain off the regulator between cooks.
Fire bans, balconies and body corporate rules
Rules on using a gas BBQ change with the day and the address. On declared total fire ban days restrictions differ between states and between councils, and gas BBQs are often treated differently from solid-fuel ones. Check current conditions with your state fire service, such as the CFA in Victoria or the NSW Rural Fire Service, before you light up.
Apartments add another layer. Many strata schemes and body corporate by-laws limit the size of LPG bottle allowed on a balcony, or ban them outright, and building rules can be stricter than state regulation. Storage limits vary by council too, so check before keeping spares.
BBQ gas bottle — frequently asked questions
How long does a 9 kg gas bottle last on a BBQ?
Most households get several weeks of weekend cooking from a 9 kg bottle. It depends on how many burners you run and how high, so a full cabinet on high empties one far faster than a single burner under a closed hood.
How do you tell how much gas is left in the bottle?
Weigh it: the difference between the bottle's current weight and the tare weight stamped on the collar is the gas remaining. A rough field check is to pour warm water down the side and feel for the cool line, which marks the liquid level inside. Clip-on gauges usually only report full, low or empty.
Can you store a gas bottle in the garage?
No, LPG bottles belong outdoors in a ventilated spot, not in a garage, shed, cupboard or under the house. LPG is heavier than air, so any leak pools at floor level in an enclosed space. Keep the bottle upright, outside, and away from drains and ignition sources.
What do you do with an old or damaged gas bottle?
Take it back to a gas supplier or swap outlet, which can assess it and dispose of it properly. Rusted, dented or out-of-date bottles must not be refilled, and must never go in a kerbside or recycling bin. Many councils also run gas-bottle drop-off days.
Shop the range
Whatever bottle you settle on, the BBQ it feeds does the real work. Our BBQs and outdoor cooking range runs from portable units through to full outdoor kitchens. A Coleman Premium BBQ Cover - Large ($75) is the cheapest protection you can give a regulator and bottle bay. We deliver Australia-wide with free delivery on orders over $100, and most orders are dispatched in 3-10 business days.
