Aboistop Anti-Bark Collar batteries differ depending on whether you have the Standard or ‘New Generation’ model. The New Generation Aboistop (recommended for dogs weighing less than 8kg) uses a Sanyo Lithium Battery. It is critical that only this type of battery is used because others will either not have the required voltage to operate the unit or will be of a slightly different shape which causes the battery contacts to be moved from their correct position.