A Mini-Breaker is a TCO device that combines overtemperature and overcurrent protection for rechargeable battery applications in a single, compact package. It is an ingenious combination of two common circuit protection technologies, a PTC and a bi-metal switch. It has two key terminals for conducting current; the arm terminal and base terminal which are connected in a normally closed position to allow current flow through the device. The contact point between both terminals is critical and a testament to the high precision of the Bourns Mini-breaker in that the contact resistance in some model families is as low as 1 milliohm (mΩ).