Calienté pad heater
Photos courtesy of Calienté
However, the third heating system is the one Calienté is most excited about. Referred to as a pad heater, this technology is used in cooling systems that have a cold plate built in. By embedding a thin heating pad into this cold plate, Calienté can bypass the coolant and heat cells directly. “The pad is right within the cold plate,” explains Kelly. “In these types of cooling systems, they bond the battery pack modules onto a cold plate to cool it. Picture a large plate with fins going up between the stacks in the modules that pull heat out of the system. We can drive heat from that plate back up through those fins into the system.”
Pad heating While Kelly is careful not to try to predict the future, he’s very optimistic about the pad-style approach for battery heating. “We always say we’ll go where the market goes, and we’ve got all three technologies,” he emphasizes. “But the pad heater seems to be the best potential fit. And that’s direct feedback from one of the larger pack companies.” Because of its novel approach in making use of the cold plate, Calienté’s pad heater offers a number of advantages over other heating solutions. “What we thought is, let’s actually embed a heater pad within the cold plate,” Kelly says. “So instead of having an isolated
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Instead of having an isolated element somewhere far away from the pack, and fluid lines that lose energy as you move the fluid through the line, we put it right at the source. element somewhere far away from the pack, and fluid lines that lose energy as you move the fluid through the line, we put it right at the source. That way we can spread the heat out much more evenly and bring the pack up to temperature in a much more uniform manner. And OEMs don’t have to worry about a certain cell getting hotter than the others, because we can vary the watt density and all that.” Furthermore, because of the small size of the heating pad, this approach doesn’t demand any trade-off to the existing cooling system. “These parts are only about eleven thousandths of an inch thick. We can put that in the cold plate and not impact the cooling performance,” says Kelly. In spite of the early promise of pad-style heating, it