The nominal capacity of a kettle refers to the maximum amount of water that can be safely poured into it, and it is typically indicated by the water level indicator. In the case of brewing sets (see "Type"), the nominal capacity refers to the main kettle, while the capacity of the teapot is listed separately (see below).
The capacity of the electric kettle directly affects the amount of water that can be heated at once. A larger capacity allows for heating more water, but this also means the kettle will be larger and heavier. Additionally, heating a larger volume of water requires either more power or a longer time. Therefore, it is important to consider one's actual needs when choosing a kettle based on its capacity. For example,
mini-kettles for travelling (or for one person) have a volume of up to 1 liter. For home use in a family of 2 – 3 people, a 1,5 – 2 liter model is enough. Devices for
2 – 3 liters are already well suited for a small office or a similar situation. The most spacious electric kettles are designed to hold 10 liters or more, and are typically used in public places such as canteens and cafes for dispensing hot water.
—
Water supply button. The electric pump button is used to control the built-in pump in the kettle, which is responsible for supplying water to the spout. It is considered to be the most advanced method of water supply as it requires no manual effort from the user, can work with any container, and allows for accurate measurement of the required volume. Some models even provide automatic dosing where the electric pump dispenses a strictly defined volume of liquid with just the touch of a button. However, these supply systems are more expensive and require a power supply, which can be a disadvantage for some users.
—
Hand pump. The mechanical pump with a manual drive is integrated into the lid of the thermopot and is operated by a large button. This type of pump is simple, inexpensive, and does not require electricity to function, which is beneficial in case of power outages. However, it is not very convenient since multiple presses are required to fill even a small cup, and it is difficult to accurately measure the amount of water dispensed. As a result, it is typically used in conjunction with more advanced systems rather than being the sole method of dispensing water.
—
Cup pressing. This method is also known as the "cup-activated dispensing system". It uses an electric pump, similar to the button systems described earlier, but the switch for
...the pump is located near the spout and is activated by the cup's edge instead of by hand. This makes it easy to dispense water by simply bringing the cup to the spout and pressing the switch with the cup's edge. However, this method is not suitable for certain types of cups such as soft plastic or paper cups, and holding the cup while dispensing can be inconvenient as the hot water can burn one's hand through the walls of the cup. Therefore, this method is often combined with a traditional serving button to provide users with the most convenient option for their situation.
