This fun feature can be found in a few of Makita's battery chargers, such as the 18V LXT Rapid Battery Charger and the 40V XGT Rapid Charger. It does not come in the 12V CXT charger. That said ...

Japanese power tool giant Makita began producing power tools in 1958 and was an early innovator of 18-volt lithium-ion cordless tools. The company refers to its existing LXT System as Willy Wonka ...