The Toniebox uses a built-in nickel-metal hydride battery, also known as a NiMH battery. It is charged using the included charging station. The Toniebox can be operated while the battery is charging without an issue.
NiMH batteries are considered very robust and offer comparatively good charging properties. This means that what is known as the 'memory effect' does not occur with this type of battery. Unlike the lithium-ion batteries used in smartphones and tablets, NiMH batteries will not catch on fire or burst.