3 Volt Battery Holder

The 3 Volt Battery Holder is the power source of Snap Circuits, and if it isn't in a kit, the 4.5 Volt Battery Holder (B3) is. All kits either have 2 3 Volt Battery Holders or a 4.5 Volt Battery Holder, unless it is the Motion Detector Mini-Kit which has the 9 Volt Battery Holder(B5), the Snap Rover kits, which can hold 6 AA batteries for 9 volts, or Snap Circuits Jr, which has 1 3 volt battery holder.