Littelfuse self-recovering overheat protection equipment increases the safety and space of polymer lithium-ion and prismatic batteries

Littelfuse, Inc. today announced the launch of its new line of MHP-TAC (Metal Hybrid PPTC - Thermally Active Compact) series of self-recovering overheat protection devices - the battery mini circuit breaker product line. This device protects high-capacity lithium-ion polymer (LiP) and prismatic cells for mobile devices and consumer electronics by connecting PPTC (Polymer Positive Temperature Coefficient) devices in parallel with bimetal protectors (self-recovering thermal shutdown devices) To prevent damage due to overheating and overcurrent.

Under normal operating conditions, current can pass through the bimetallic contacts due to its low contact resistance. In the event of an abnormality, the device reacts to an increase in battery temperature, causing the bimetallic contact to open at a particular temperature and its contact resistance to increase. At this point, the current is shunted to a PPTC that acts as a heater and has a lower resistance, helping to keep the bimetal protector open and in the locked position until the fault is removed.

Lithium-ion polymer batteries and prismatic cells typically have small size, high battery capacity, and high battery discharge rate requirements. Circuit protection devices have low thermal resistance temperature (<90oC), high holding current rating (>6A), and compact size. Compared to other devices of its kind, the MHP-TAC series offers higher voltage ratings and holding currents, as well as more temperature rating options, and is slimmer and smaller, which reduces the space requirements of the battery pack design.

Typical applications for the MHP-TAC series of self-healing overheat protection devices include lithium-ion polymers and prismatic batteries for battery-powered devices such as laptops, ultrabooks, tablets, smartphones and e-cigarettes.

Author：Brittany Antonia （The author of article owns the copyright.）