WEBVTT 00:00:00.265 --> 00:00:04.180 Can we cool a battery’s terminals without risking an electrical fault? 00:00:04.570 --> 00:00:06.525 Look inside the real prototype, 00:00:06.675 --> 00:00:09.240 then see what Lemonergy checks before we build. 00:00:10.050 --> 00:00:14.200 Lift the cover to see the pouch cells between the front and rear cooling plates. 00:00:17.455 --> 00:00:19.445 A jumper hose links the plates. 00:00:19.715 --> 00:00:23.325 In the close-up, the busbars transfer heat into the coolant tube. 00:00:23.665 --> 00:00:26.230 The amber strip is the voltage-sense cable. 00:00:28.005 --> 00:00:31.455 The insulation keeps the busbar and tube electrically separate. 00:00:31.845 --> 00:00:36.365 Hand-bent busbars and thicker tubes sometimes squeezed that gap too far. 00:00:36.725 --> 00:00:40.185 Control the spacing and test isolation after molding. 00:00:40.798 --> 00:00:44.278 The cut section tells us what to check inside the plate. 00:00:44.278 --> 00:00:47.508 At pack level, let’s start with a separate storage example 00:00:47.508 --> 00:00:49.238 in Lemonergy Pack Designer. 00:00:49.598 --> 00:00:52.438 Import the design with cooling underneath the cells. 00:00:52.695 --> 00:00:55.725 Save it as our baseline. Now we have a reference. 00:00:55.975 --> 00:00:59.615 When we add cooling near the tabs, we can see exactly what changed. 00:00:59.862 --> 00:01:03.602 Import the combined case and compare it with the saved baseline. 00:01:03.942 --> 00:01:05.992 The bottom cold plate stays. 00:01:06.322 --> 00:01:08.932 The change is in the cell interconnect carrier, 00:01:08.932 --> 00:01:11.192 where we propose a second coolant route. 00:01:11.465 --> 00:01:13.605 Follow the new route above the cells. 00:01:13.905 --> 00:01:15.855 The layout tells us where it goes. 00:01:15.855 --> 00:01:18.935 To find out if the connections can carry the load, 00:01:18.935 --> 00:01:20.415 open the engineering audit. 00:01:20.695 --> 00:01:22.375 Pause on the joint warning. 00:01:22.715 --> 00:01:25.675 At the chosen load, the current through each cell joint 00:01:25.675 --> 00:01:28.235 exceeds the allowance used for this library part. 00:01:28.235 --> 00:01:30.995 Can we reduce the current through each joint? 00:01:31.318 --> 00:01:33.168 Think about the path the current takes. 00:01:33.468 --> 00:01:35.668 With one string, the same pack current 00:01:35.668 --> 00:01:38.088 passes through every cell joint in that string. 00:01:38.372 --> 00:01:41.232 Now put two cells in parallel in each series group. 00:01:41.232 --> 00:01:45.602 If the two cells share evenly, each carries about half the pack current. 00:01:45.882 --> 00:01:46.832 Will that be enough? 00:01:47.132 --> 00:01:50.822 Lemonergy shows that the larger layout still fits the envelope. 00:01:51.142 --> 00:01:54.282 We gained a second path by using twice as many cells. 00:01:54.600 --> 00:01:56.090 Now look at the audit again. 00:01:56.360 --> 00:01:59.300 The current per joint fell, and the check still fails. 00:01:59.600 --> 00:02:02.780 Our next design change is a joint rated for this duty. 00:02:02.780 --> 00:02:04.560 Then we can run the check again. 00:02:04.872 --> 00:02:07.712 The joint warning tells us what to change in the pack. 00:02:07.992 --> 00:02:11.082 There’s a separate question about the coolant path. 00:02:11.082 --> 00:02:12.772 How much faster can it remove heat? 00:02:12.772 --> 00:02:15.872 Let’s return to the pouch module we opened earlier. 00:02:16.163 --> 00:02:19.423 In Lemonergy Simulation Studio, both cases start warm 00:02:19.423 --> 00:02:21.603 and lose heat to the same room. 00:02:21.993 --> 00:02:25.633 The active case also has a path from the tabs to the coolant. 00:02:25.903 --> 00:02:27.093 Open that path. 00:02:27.353 --> 00:02:30.543 Here the model uses the difference between module temperature 00:02:30.543 --> 00:02:33.373 and coolant temperature to calculate heat flow. 00:02:33.653 --> 00:02:36.093 Heat must travel along the thin nickel tab 00:02:36.093 --> 00:02:39.283 and across its clamped contact with the busbar. 00:02:39.283 --> 00:02:40.353 Both resist heat flow. 00:02:40.603 --> 00:02:46.343 For the whole pouch module, Fraunhofer reported 0.91 W/K for the tab path. 00:02:46.733 --> 00:02:49.553 The simulated seam path was 2.33 W/K. 00:02:49.853 --> 00:02:53.393 That supports testing tab cooling alongside the main cooler. 00:02:53.733 --> 00:02:56.993 The gain for our proposed pack still has to be demonstrated. 00:02:57.288 --> 00:03:01.338 Back in Lemonergy, run both cases from the same starting temperature. 00:03:01.728 --> 00:03:05.128 Here we compare air cooling alone with air plus tab cooling. 00:03:05.423 --> 00:03:07.533 Watch the blue curve fall faster. 00:03:07.783 --> 00:03:10.303 The extra path carries heat out of the module. 00:03:10.583 --> 00:03:13.823 Each curve represents the module as a single temperature. 00:03:14.203 --> 00:03:18.013 To see what happens at a hot spot, we need sensors on hardware. 00:03:18.308 --> 00:03:20.568 That’s where the charging experiment comes in. 00:03:20.908 --> 00:03:25.008 Fraunhofer charged the same prototype with tab cooling off and on. 00:03:25.308 --> 00:03:27.828 We’ll compare the highest reading on the center cell. 00:03:28.142 --> 00:03:32.212 With tab cooling on, that peak was 16.2 °C lower. 00:03:32.212 --> 00:03:34.852 That’s the benefit measured on this prototype. 00:03:34.852 --> 00:03:37.802 What does it take to keep the coolant moving? 00:03:38.090 --> 00:03:41.560 Multiply the coolant flow by the pressure drop across the plates. 00:03:41.560 --> 00:03:47.050 At the published test point, that gives 1.7 W of hydraulic power 00:03:47.050 --> 00:03:48.610 through that section of the loop. 00:03:48.933 --> 00:03:51.903 For the electrical estimate, include the rest of the loop 00:03:51.903 --> 00:03:54.613 and account for pump efficiency. 00:03:54.613 --> 00:03:58.483 In our illustrative example, the pump draws 16.7 W. 00:03:58.803 --> 00:04:01.173 Cooling equipment uses power separately. 00:04:01.497 --> 00:04:03.567 So where does that leave us? 00:04:03.567 --> 00:04:07.877 The experiment shows why cooling near the tabs is worth investigating. 00:04:07.877 --> 00:04:10.367 For our pack example, choose a suitable joint, 00:04:10.367 --> 00:04:14.357 rerun the checks in Lemonergy, and measure temperature, flow, 00:04:14.357 --> 00:04:16.887 and electrical isolation on the prototype. 00:04:17.173 --> 00:04:18.743 Then price the whole system. 00:04:19.053 --> 00:04:24.483 Include the interconnect, plumbing, pump, assembly, testing, and operating energy. 00:04:24.863 --> 00:04:27.713 Compare it with the original bottom-cooled design. 00:04:28.043 --> 00:04:32.243 Now you have the evidence to decide whether the added cooling earns its place.