How Does a Cordless Kettle Work?

The cordless kettle has been kicking around in kitchens and homes for around 30 years and has provided users with greater flexibility in these spaces. As time continues to march forward, they have become safer to use, more energy efficient, and with greater durability they last longer and cost less than kettles of the past. 

But what goes into a cordless kettle? How does a cordless kettle work? What safety features do they have? And finally, what are the best available?

What is a cordless kettle?

The cordless kettle has existed for several decades now and has become a popular design amongst users. They offer convenience, safety, and speed in kitchens and offices around the world to get your brew to you. 

While a kettle may be referred to as a ‘cordless’ kettle, this is often misconceived as being a completely remote and independent design that operates on batteries, or has a rechargeable element, but this is not quite the case. In fact, the cordless kettle is likely something you have experience of using. It simply means that the kettle can be detached from the base and taken anywhere. There is no wire to limit the movement of the kettle itself before or after it is boiled. 

This functionality can be summed up in one word: freedom. With the ability to transport the kettle once it is boiled, it can be deployed anywhere it is needed. Deicing a windscreen, filling a bathroom sink, and of course: filling a cup on the other side of the kitchen. The mobility allowed by a cordless kettle means it adapts your needs, not the other way around. 

Though you have likely used a cordless kettle, you may be wondering quite how it works. If you open up your kettle you might just see a heating element at the bottom. With the kettle sitting on a plugged-in base and the switch turned on, an electrical current will flow to the heating element where it will meet resistance that transforms the electrical energy. As energy can neither be created, nor destroyed, the resistance will cause the electrical energy into heat which then transfers to the water, leading it to boil.

The anatomy of a cordless kettle

There are three parts to the cordless kettle: The detachable 360 degree base; The kettle body; The connector system. They are designed to provide ease of use and safety in all the spaces the kettle will likely be present. 

Though the detachable 360 base and the connector system are a part of the same system, they have different functions that lead to a better overall experience. 

The base is the power hub that connects to the household outlet via a cable which allows an electrical current to flow to the kettle. Its circular design means the kettle can be placed, lifted, and turned at any angle, making pick up and put down easy and comfortable for any user. This is especially handy for those who are left-handed. 

Part of the base is the connector system that allows power to transfer to the kettle itself. The male connector sits in the middle of the base and connects to the female socket on the underside of the kettle. The copper strips, rings, and pins join together to complete the circuit, which then allows for electrical energy to transfer to the heating element in the kettle. 

The body of the kettle, which can also be referred to as the reservoir, is what holds the water. They are typically made of stainless steel, glass, or food-grade plastic and have multiple functions in the water boiling process. Acting as the container, heater, then pourer of water, there are so many elements that need to work together that must be factored into the design.

How does a cordless kettle work?

The kettle is full, placed on the base, the switch is on and the water begins to boil, but how did we get here? 

Once the switch is activated, a large electrical current will flow from the outlet, through the base, and pass through the connection system into a concealed heating element at the bottom of the kettle. 

The heating element is arguably the most complex part of the kettle. Not only does it need the electrical power to heat the water, but it must remain completely safe so that it can survive the rigours of regular use.

Once the current reaches the kettle, high resistance materials such as nichrome wire (a nickel-chromium alloy) insulated with magnesium oxide will act against this flow which triggers the transformation of the energy. As energy cannot be created or destroyed, the resistant wire allows for the electrical energy to be transformed into thermal energy. 

With the heat rising from the components at the base of the kettle, the atoms in the water will begin to vibrate driven by this new thermal energy. As the temperature continues to rise, the vibrations will become faster and small bubbles will begin to escape. Once the molecules have gained enough energy, they will change from a liquid to a gas and the water will be boiled. When the water has reached this point, the switch will flip and the current will cease and the kettle is now yours to pour over whatever you choose. The auto-switch off means a consistent boil every time and no excess kettle usage, saving on the electricity used. 

Are cordless kettles safe?

With the proximity of water and electricity naturally comes a potential hazard. Kettles are often found in kitchen or office environments where a fault or hazard could lead to serious consequences and potential injuries for users and the surrounding environment. 

For cordless kettles to be as consumer friendly and widely available as they are, is in itself a testament to their safety features. There are numerous mechanisms in place to ensure that users aren’t harmed when using them including thermostats, bimetallic discs, boil-dry protection, and external layering as well. 

For the kettle to know when to stop boiling, there is a bimetallic disc, made of two metals with different boiling points, found near a switch in the kettle. As the water boils and  steam passes through a channel in the disc, the metals used will expand unevenly causing them to bend. As the water is imbued with more energy, the bimetallic disc will continue to bend as one metal is softer than the other, eventually reaching to a switch which will break the circuit and turn off the kettle. At this point, the water is ready to be poured. 

Another safety feature found in kettles is Boil-Dry Protection. ‘Boil dry’ is when a heat source continues to operate with no water in the appliance. This can occur when there is no water in the appliance to begin with and it was accidentally turned on, or if left unattended and all the water that was present evaporates. With no water in the kettle for the thermal energy to transfer to, the heating element will continue to get hot which can cause permanent damage to the kettle itself, or even start fires. To avoid this, Boil-Dry Protection kettles have sensors inside them to detect for water levels or the extreme heat that can occur and will automatically shut off the kettle. This will maintain the integrity of the kettle and ensure it will remain usable for the foreseeable future.

Not only are the interiors of kettles more protected, but so are the exteriors safer for all kinds of handling. Double-wall ‘cool touch’ exteriors are designed to prevent burns if the kettle ever needs to be supported by the body along with the handle. This extra layer protects exposed skin from being burnt by a boiling kettle before it has had the chance to cool down. 

Are cordless kettles worth it?

There are so many benefits to having a cordless kettle in your kitchen. Kettles made today offer so much freedom and safety around the home that it really is a no-brainer. 

With no cumbersome cords tying you to one corner of the kitchen, no need to worry about electrical exposure to water, or any boil-dry damage causing fire, kettles made today are as good as they have ever been.

As the mechanics in a kettle have developed over centuries, they are now more reliable, efficient, and safer than ever. Kettles are made so that your brew is exactly how you want it every time. No more burns as you pick it up, no more rampant limescale build up, no more limitations on where you can take your kettle. 

Not only are kettles safer and more mobile, but they are also far more energy efficient than previously popular models such as the stovetop. With automatic switch features when the water is boiled, no more unnecessary energy is used, meaning more efficient appliance usage and lower bills. 

What are the best cordless kettles?

Morphy Richards offer a strong range of cordless kettles and here are three of our favourites: