By John Baichtal
Problem: A major telecom customer needed to thermally stabilize a battery pack used in a high-altitude application. The pack was part of a payload kept in the stratosphere for weeks or even months at a time. The battery pack wouldn’t operate below freezing, and a heater was needed to maintain the pack at its optimal temperature range. Weight was an issue, so the solution had to be as simple as possible. At the same time, reliability was absolutely a factor because if the battery failed, the project would abort.
Solution: Minco’s SmartHeat SLT™ (Self-Limiting Technology) heaters were able to maintain the batteries’ safe and uniform operating temperature without the added weight and complexity of controllers or sensors.
This technology represents a dramatic change in the way heaters are constructed. Each heater is designed and manufactured to achieve and maintain a specific temperature. A carbon-silicone matrix (CSM) comprises the core of the laminated heater circuit. When powered up, the silicone expands and the CSM’s resistivity increases, allowing the SmartHeat SLT heater to automatically “self-tune” to a specific temperature. The CSM pinpoints precisely when and where heat is needed to maintain uniform heatsink temperature. The resistance of the polymer increases exponentially at a prescribed temperature control point.
Engineers specify SmartHeat heaters in part because the technology makes it possible to eliminate multiple components—sensors, controllers, cutoffs, and other instrumentation–used in a typical heating system and replace them with a single self-limiting heater. This heater can be designed to operate at a specified temperature without the need for a sensor or controller, and the self-limiting nature of the technology prevents overheating, eliminating the need for safety cut-off components like thermal fuses. SmartHeat heaters’ CSM also automatically evens out the heat delivered. Point by point, the matrix senses heat sink temperature, upping power on an individual part of the matrix while maintaining the rest of the heater. In extreme cases, the heater can even operate partially separated from its heat sink, and no overheating or thermal runaway is possible.
SmartHeat technology has been used in high-altitude applications like battery warming and aircraft de-icing, but also finds use in hospitals for IV fluid warming, reagent storage, and stabilizing handheld point-of-care devices. Find out more the technology by downloading our SmartHeat SLT white paper or by consulting with our Frequently Asked Questions on the subject. When you’re ready, contact Minco to prototype a custom solution for your next project or peruse the selection of heaters we offer on our online store.