With all the Rokenbok toys you are purchasing this Christmas, disposable batteries can not only be expensive but bad for the environment.
Disposable batteries are by far the most expensive way to use energy. Depending on the type, capacity, and cost of the battery, disposable batteries carry a price tag ranging from $400 to over $20,000 per kilowatt-hour. In contrast, the cost for using rechargeable batteries is less than $1.00 per kilowatt-hour.
A wall charger and 4 AA rechargable batterie