All of our Sphero products utilize rechargeable Lithium Ion batteries as a power source. In designing our products, we made it a point to use the highest-quality, stable Lithium Ion batteries possible, optimized for a balance of safety and performance. 


For more details, please see our best practices and safety conformity documents, here: 


If you have any questions or concerns, please let us know at support@sphero.com, we're always happy to assist.