How Better Battery Vents Are Powering Safer Electrification
EV safety hinges on the reliability of every component—especially those related to the battery system. Failures, even in small parts like battery pack vents, can significantly impact public trust by triggering dangerous events such as thermal runaway, fires, or explosions. Recognizing this, the SAE Battery Pack Venting Committee developed the SAE J3325™ Technical Information Report. This guide supports engineers in designing, testing, and integrating effective battery venting solutions to enhance EV battery safety. Dr. Michael Harenbrock of MANN+HUMMEL, who chairs the committee, highlights how this collaborative effort is critical in adapting to new ventilation technologies and ensuring the electrification ecosystem evolves safely.
Transcript
00:00:01 There's a lot changing in electrification and there are some consumers that see a news, oh, I can't buy an electric vehicle because it might it might catch on on fire or I saw this on the news, right? Or I saw that on the news and that there's a lot of misinformation and a lot of concerns. Overall, do you think globally consumers
00:00:19 trust that their batteries and electric vehicles are safe? I would say so. Um you know at the end of the day um sales volumes of electric vehicles are steadily increasing especially also in China nowadays you know we have regional trends um there's um investigations from insurance companies which compare the likelihood of a vehicle uh to catch fire and what they found out is that battery
00:00:43 electric vehicles are even less prone uh to fires than vehicles with internal combustion engines. And so at the end of the day, the vehicles are already pretty safe, but you know, you never know what happens. So you could have some extreme conditions like flooding events, something like that, which could also lead to battery fires. And of course, if um severe events happen, that can really
00:01:07 give a bad name to the whole industry. And that's why we all should strive for making it even more safer. And that's also what um current and upcoming regulations on battery safety really mandate. To me, it's that once an individual drives an electric vehicle and lives with it, you can't go back. I am I'm on my second EV. I can't go back. It's it's the convenience and and it's
00:01:28 it's heavier. You feel cuz you're you feel you're you're hugging the ground better. It just seems that to get over that hump of individuals drive and live with it that though those fears tend to go away. But I think which is which is really neat what you're working on is battery pack fence. That was fascinating from a safety perspective. Where do those come into the picture?
00:01:48 What do they do? You know, if we talk about battery safety, we always have to see that we have so-called holistic battery safety management uh systems. So it starts with the battery cell to make sure that um the cell is okay, no production items whatsoever and ends up with the vehicle integration. And so battery pack vents are somewhere in between uh battery cells in the vehicle.
00:02:10 So on on they help the battery pack to to fulfill its task. And those vents often have two functions. On one hand uh they enable pressure equalization between the battery pack interior and the ambient atmosphere. And on the other hand, they enable the fast uh relief of over pressure caused by vent gases uh which are created by battery cells if they run into malfunction. Uh something
00:02:36 called some runaway event for example. And here um that's really a very important um function those units can also do. How do the vent vents function? Are they on the sides of the vehicles, the back of the addition to a tailpipe or or where do the vents push out those gases? Yeah. So there's there's really no um let's say mandate where to place it. Um so normally what I'm in favor of
00:03:02 is to place it on um battery walls. So the the vertical ones um because if you put it on the top of the battery pack, you could run the risk that vent gases are guided towards the passenger compartment and the cabin. And so this would mean that we have a higher risk of vent gases getting into the cabin. And those gases can be um toxic, they can be harmful. And so this is something to be
00:03:27 avoided. So my personal preference is to put it on a vertical battery wall facing uh towards the rear section where you would have the exhaust pipe in regular um vehicles with internal combustion engines. You're the chair of the SAPE battery pack venting committee. You're working on the SAPEJ 3325 technical information report. Is that an example something the group is is working on of
00:03:51 if you want to call it a best practice of where those gases should exit? Yeah, absolutely. But before I go more into that just wanted to uh thank on one hand SAPE and also the committee members to make me chair. Um it was really an excellent experience great teamwork and I really loved to lead the activity uh leading to this uh information report. Um so um I think that there's a common
00:04:17 understanding that that would be a good solution but at the end of the day it really depends on the actual pack design um where those vents have to be placed. Um you can have several vents also placed let's say in um in the longitudinal um walls. Um but then you would still have to have some um guidance um how they exit the gases exit um the vehicle structure. So the chassis
00:04:41 in general and that is something that's very much depending on the actual pack and then also vehicle design. So this also plays a role.