YOU SHOULD NEVER EVER MAKE A REAL SHORT CIRCUITS AS IT WILL DRAIN BATTERY AND/OR DAMAGE PARTS. You can actually make a short circuits on the snap circuits battery holder. There is a thermal fuse that will prevent real short circuits. It will not protect RV from damage, so that's why Jeff and Jerry started putting resistors on the RV. Without the thermal fuse, A1 may be damaged on attenna storing energy project, and the batteries may be drained.