How long should a 45kg gas bottle last?

In this blog post, we will answer the following question: How long should a 45kg gas bottle last? We will discuss the consumption rate of a 45kg gas bottle in an RV, explain how to calculate the autonomy of a gas bottle and review other important and interesting facts about RV gas consumption. 

How long should a 45kg gas bottle last?

How long your 45kg (100 lbs) propane bottle will last will depend on the fuel consumption of your camper and how much you use it. One gallon (3.7 L) of propane gas offers 91,500 BTUs of thermal energy and weighs 4.25 pounds (1.9 kg), which is equal to 21,500 BTUs of heat energy per pound of propane gas. 

If your camper heater uses 26,000 BTUs per hour, you will receive 50 minutes of burn time per pound of propane gas. You will consume a little over a third of a gallon of propane gas per hour or three and a half hours burn time for every gallon (3.7 L) of propane gas.

If your camper heater uses a pilot for lighting, the flame consumes about 600 BTUs per hour or 14,400 BTUs per day, which is equivalent to about a gallon of propane gas or about 4 pounds (1.8 kg) of propane each six days.

Examples of how long a 45 kg gas bottle will last:

  • At a consumption rate of 26,000 BTUs per hour, your 100-pound bottle (45 kg) will run your propane fireplace for approximately 84 hours, which is equivalent to 3.5 days of continuous 24/7 operation. 
  • If you use your propane fireplace for two hours a day, seven days a week; the 100 pounds (45 kg) propane bottle will run your fireplace for almost six weeks.
  • If you use your fireplace for four hours a day, the bottle will last for about three weeks. Similarly, if your fireplace uses 52,000 BTUs per hour instead of 26,000 BTUs and you use it for two hours a day, you could use it for about three weeks from your 100 (45kg) pound bottle.

How to calculate the autonomy of a gas bottle?

In order to estimate the gas cylinder autonomy for the device of your choice, you just need to find the gas consumption of the device in g/h. Then, all you have to do is do the following calculation:

Amount of gas in the cylinder (kg)/consumption (kg/h)

For example, for a gas cylinder supplying a barbecue with a maximum consumption of 915 g/h, you have to do the calculation 13/0.915 = 14.21. We can therefore estimate that at maximum power, the bottle can be used for at least 14 hours.

Since it is rare to use the device at high power continuously, we can estimate that the autonomy of a 13kg gas cylinder will be greater than 14 hours.

Can we increase the consumption of a gas cylinder?

It is not technically possible to increase the autonomy of a gas cylinder, but the autonomy of the entire installation can be extended by associating several cylinders with one another. Using a reversing coupler, it is possible to connect several gas cylinders from the outside or inside so that they supply all the desired devices.

The reversing coupler can be automatic or manual and is used to switch from one bottle to another when one of them is empty. There is therefore no risk of gas failure since the consumer can use another bottle before going to exchange the empty one.

The advantage is that it makes it possible to identify whether a bottle is empty or full and above all which one.

An installation with a reversing coupler does not dispense with the presence of regulators in order to limit the gas pressure. Two solutions are possible for the installation of butane bottles indoors:

  1. A pressure reducer is connected above the reversing coupler and shut-off valves are connected to each device;
  2. Each device has a safety trigger regulator.

In the case of an installation of propane cylinders, which must be done outdoors for safety reasons, a pre-regulator precedes a pressure limiter at the cylinders. Then, each device has a safety trigger regulator.

What factors impact the autonomy of a gas cylinder?

The autonomy of a gas cylinder varies according to several factors and in particular the type of device supplied. If this device is energy-intensive, the gas cylinder will last less.

Likewise, if the use is intensive (ignition of all the hotplates on a gas stove, for example), the autonomy will be considerably reduced. It is therefore difficult to estimate with precision the autonomy of a gas cylinder as it varies from one use to another.

What type of gas to choose for an RV?

If you are looking for a gas cylinder for your motorhome, know that you will have to choose between two types of gas, depending on your uses:

  • Propane gas cylinder: If the cylinder is connected to the passenger compartment from the outside. It is a cold-resistant LPG and remains effective at temperatures down to -44 ° C.
  • Butane gas cylinder: If the cylinder is stored inside the vehicle.

What is the ideal dimension for a motorhome gas cylinder?

For travel by caravan or motorhome, the gas cylinders should be small to medium size. These dimensions are sufficient to reconcile power and autonomy on the roads.

When the cylinder is placed outside, provide a 5 kg propane cylinder or a 13 kg propane cylinder. Inside, bring a 13 kg butane bottle, a small 10 kg Calypso butane or a 5.5 kg Elfi butane. The latter two sizes have the advantage of being easy to set up and transport.

How do I know how much gas is in my cylinder?

Here’s how to check how much you have left in your gas cylinder:

  1. Fill a jug or bottle with hot tap water.
  2. Pour it over the side of the gas cylinder.
  3. Wait 5 seconds.
  4. Using your hands, feel a change in temperature on the bottle.
  5. The cool-to-touch portion will indicate the amount of gas remaining. If it’s cold near the top, you’re fine. If it’s hot all the way down, you may need to replace the gas bottle soon. 

Do the gas cylinders expire?

Gas cylinders have a date stamp applied during manufacture. A bottle over 10 years old, must be rigorously inspected before it can be refilled. The inspection should be carried out by an approved tester. Once the bottle meets government safety standards, the tester will re-tampon it for an additional 10 years of filling.

How to change a gas cylinder?

To change a gas cylinder you’ll have to:

  1. Turn off the flywheel of the empty gas cylinder (clockwise).
  2. You then move the switch valve lever to point at the other (full) gas cylinder.
  3. Turn the handwheel on the full gas cylinder to ON (counterclockwise).

Remember to order a replacement gas cylinder so you don’t run out!


To supply the uses of a motorhome, you can buy a bottle of butane or propane gas. The choice of gas is made according to the location of the storage: if it is inside, we opt for butane and if it is outside, we choose propane.

Now that you have a better understanding of how your RV uses gas and how long a cylinder lasts, you are ready to hit the road with confidence, for a comfortable and economical trip!

Please let us know if you have any questions or comments on the content. 

FAQ on How long should a 45kg gas bottle last?

How long does a 4.5 kg gas bottle last?

A 4.5 kg gas can last you up to two-three days of camping, or 8 hours of continuous use. However, the autonomy of a gas cylinder depends on several parameters, in particular, the expected consumption and the power of the connected devices. Focus on these two elements when estimating the lifespan of your 4.5 kg gas bottle.

​​How long can a 6Kg gas cylinder last in an RV?

A 6Kg gas cylinder can last you up to 12 hours of continuous use in an RV, but in reality, the consumption time is very relative. 

How long will a 9kg gas bottle last in a caravan?

A 9kg gas bottle will last about a week in a caravan, depending on how it is used. You may think that is more than enough for a short trip, or you may think that a 9kg gas bottle will not suffice. You are right either way, since it all depends on personal preferences, number of persons on board and frequency of use. 

How long does a 19kg gas bottle last in a static caravan?

​​A 19 kg gas bottle will suffice for a few days or even a week in a static caravan. It will all depend on how many appliances you have. However, in winter, when heating is used, it will be necessary to provide several 19 kg gas cylinders, which can optionally be connected using an inverter-coupler.


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