# Understanding the Kia EV9 High-Voltage Battery

## Метаданные

- **Канал:** WeberAuto
- **YouTube:** https://www.youtube.com/watch?v=T4zXp7RhDPI
- **Источник:** https://ekstraktznaniy.ru/video/44262

## Транскрипт

### Segment 1 (00:00 - 05:00) []

Hello, I'm Professor John Kelly and this is the Weber Auto YouTube channel. Did you know that there are 456 lithium ion cells in this 2024 Kia EV9 extended range battery SUV behind me? I'm going to show you the individual cells and how they're configured and how they fit inside the battery to create the high voltage and high amp hours that are needed to drive this vehicle down the road. So, let's get started. Okay, this is what is called a pouch cell. A pouch cell typically is long and flat uh not very thick. uh it'll have a negative terminal either on one side and positive on the other or some of them will have positive and negative on the same side. Just depends on the configuration. Some are more squarel like rather than this long skinny uh pouch, but this is a pouch cell. This cell is made by a subsidiary of SK Innovation called SKON. As far as what I've been able to find, this uses the NMC uh chemistry. Now, this cell has a nominal voltage of 3. 63 volts. So, let's take a voltmeter and we'll measure from the negative side to the positive side. This is not high voltage. I don't need high voltage gloves for this. Go from negative to positive. I'm getting 3. 772 volts. So, this cell is charged a little bit higher than nominal voltage. When I charge this Kia EV9 behind me to 100% and go in on the scan tool data list, uh the cell voltages are approximately 4. 12 volts maximum. I don't know what the minimum is. I haven't run it down to 0% state of charge yet. But anyway, this is one pouch cell. It is rated for 60 amp hours. Now, 60 amp hours is a pretty good rating for this size of a pout cell. As an example, on my own personal electric vehicle, it uses 60 amps to drive 70 mph down a flat freeway here in northern Utah. So, at 60 amp hours, I could drive for approximately 1 hour. So, on this big Kia EV9 back here, you need to be able to drive farther than just 1 hour's worth of driving before you need to recharge the battery. So they increase the amp hours of the battery by adding more cells like this in parallel. So that means they're going to take three of these cells at 60 amp hours each and they're going to connect them all together. all three negatives together on one side. They'll connect all three positives together on the other side. And that triples the amp hours. Now we're up to almost 180 amp hours, which gives you approximately 3 hours of driving uh on my own personal electric vehicle. I have not been able to drive this Kia, so I don't know what it uses at 70 mph on a flat interstate freeway. But now I'm going to bring in what's called a module where we have sets of these three parallel cells. Okay, you can see this stack of cells right here. Here's more of the exact same cells. I just removed this one from this stack. But if you look closely, you can see, and let me just sit this one back on top here. There are three of them in parallel right here. Then there are three more. And then three more and three more. So there are four stacks of three parallel cells in one module right here. Now, I've removed the outer covering of the module, and I'll put it together here so you can see it in a few minutes. But inside of this module, there are three parallel sets of cells. These parallel sets are put in series with each other. Which means the positive end of this cell is connected to the negative which connects to the positive end of the next cell pack and then to the negative uh end of the next cell pack. And so it's like putting flashlight batteries in an old flashlight. Positive, negative, positive, negative. And now if we were to measure the voltage of all four of these put together, it should be that 3. 772 volts that I measured for the single cell, but this time it should be multiplied by four. Okay, I'm going to turn the cell stack so you can see the ends over here. Here's our overall negative terminal. Here's our overall positive terminal of all of the four uh cell stacks put in series. Let's measure

### Segment 2 (05:00 - 10:00) [5:00]

from the negative down to the positive. I get 15. 09 volts. And if I divide the 15. 09 by four, which is the four stacks of three cells each, then it's exactly 3. 772. So these cells add together to increase voltage when you put them in series with each other. They increase amp hours when you put them in parallel with each other. So this 60 amp hour cell that I have right here, we've got 60, and 60. So that's 180 amp hours, but that's only at the 3. 6 volts. Now we have 15 volts because we put four of those in series with each other. And then when we go to the battery where one of these modules goes, they have 38 of those in series with each other. So if you look at this photograph right here, you can see all of the additional modules that are inside of this battery for the Kia EV9. Each one of them look just like this uh on the inside. So if we take the 15. 02 02 volts of this module and we multiply it by the 38 modules that equals 570. 76 volts. And with this battery fully charged, the overall maximum voltage of this battery ends up being 626. 24 volts. So it's not an 800vt battery in the extended range EV9. And the standard range battery still has the same 12 cells in each module, but instead of having groups of three, they just have groups of two. They have six groups of two parallel cells, which means the amp hours uh are only 120, but then they have uh more of them in series with each other to bring their voltage up on that one to 716 volts. So, it's still not even 800 volts. We either have 626 volts on the long range or 716 on the standard range. I thought it was an 800vt battery, but it's close. Okay, let's look at the rest of the parts of this module and then put the module back together and compare it to what's in the battery over here. Okay, I reinstalled the pouch cell that I removed. It's still disconnected because I had to cut the terminals. Okay, the next thing to go on is the side cover that covers this pouch here. By the way, these pouches are glued together. This side cover is glued onto the side here. But in this side cover, there are two temperature sensors. One at the bottom and one at the top of this little printed circuit, flexible printed circuit there. Uh the one at the bottom is called a sub temperature sensor and the one at the top is just called the temperature sensor. Not every module in the Kia EV9 has its temperature measured, but every module has the temperature sensors. So, this fits right here. Uh there's a wire harness that goes across here because the battery monitoring computer has to monitor the cell voltages or the cell group, the groups of three uh voltages. It has to monitor those for imbalance and balance them to try to get them all to be within the same small range like 40 molts for maximum performance. Okay. So, this cover with the wire harness on the harness goes to a printed circuit board on the end of the module right here. And it just think of it as voltmeter leads that connect to the ends of these pouch cells on one side. And so this electrical connector is going to plug in to it right there. And then on the other side, we've got another electrical connector that comes down and plugs in to a circuit board that does the same job here on the other side. There we go. Okay. As you can see, I have the side cover installed with the wire harness for voltage sensing. And there's two wires, four wires that go to the two temperature sensors, power and ground for each one. Okay. Around the outside of these plastic covers is a metal cover. So, a metal box almost. Here's the box right here that goes around the outside of these. So, let me get that installed. There we go. So now we've got the side the metal side shields on each side. And now

### Segment 3 (10:00 - 15:00) [10:00]

let's tip it up and let it rest on the bottom. So we've got the two sides. Then we have an upper cover that has a metal bracket that is welded in place. Make sure I get it facing the right direction. and it comes in and sits right there with a some spot welds that hold it all together like that. All right. So, we've got the upper portions of those cells protected uh on the top here. The bottom are still exposed, though, and I'll explain why here in just a moment. But there are some end caps now that go on to the ends of these stacks of cells. So, we'll slide that one on right there and put some screws in it. Okay, we've got the one end cap on. It has an opening right here for an electrical connector for the cell monitoring unit. It's a little uh computer. There are seven of them that monitor all 38 of these modules. But there's an electrical connector that plugs into here for measuring the cell voltages and the temperature sensor. And now on the other side where our uh negative and positive terminals are, there's another end cap that fits right there with some screws. Okay, I've assembled the complete module. It has all 12 cells in it that we just saw. This is in a protective housing. And we have, as you can see right here, the negative and positive terminals. And then another one of these modules would sit right next to it. And the positive of this module would connect to the negative of the next one. So this is a 15vt module, 16 volts, a little over 16 volts when it's fully charged. If we put it in series with another module right next to it, then it becomes 32 and then 48 and 64 and so on. Clear up until our maximum battery voltage of 626, I think. Now that it's back together, we can look underneath it. You can still see the four groups of three parallel cells each. However, this is the bottom of the module, and these cells need to be able to transfer their heat energy into the coolant. There's a coolant plate in the bottom of this battery, and we need to transfer the heat energy from these cells into the coolant so that they don't overheat. Now, when I bought this used uh module from uh on eBay, the bottom of this of all these cells was coated with this gray. It's not sticky. It's more like uh clay Play-Doh. It had a thin sheet uh that went all the way across and it makes contact with the bottom of the cells coolant plate to transfer the heat energy uh into the coolant. There's a special fixture if you read in the Kia service information. There's some special service tools and a guide and a big caulking gun type thing with a big wide uh outlet that you run along the bottom of where this module is going to sit inside of the battery housing and it lays down this thermal interface material Tim and then you set the module on top of that and then never move it again. If you take it back off, then you got to scrape all that out and replace it. Okay, let's take this module over to the battery and see where it would fit. Okay, as you can see, we have the individual modules in this entire battery here with the cover removed. Uh, this one that I took apart over on the bench, uh, is a used one I purchased off of eBay. So, it is not going inside this battery, but as you can see, it's the exact same one. It came out of a Kia EV9. And we just have these modules lined up in series with each other. This is module one right here. This is module 38. And they are in series going back and forth, back and forth on about this 2/3 side of the battery. And then continuing on this side until the end over here on number 38 on the other third of the battery. Going down the middle there, we have the cell monitoring computers that monitor the individual cell voltages in these modules and the temperature sensors. And then we have a 500 amp fuse and a battery computer over there on the other side. I have another video coming up on the overall battery. We still have parts of it that are

### Segment 4 (15:00 - 15:00) [15:00]

disassembled, but in this video, I wanted to dive deeper into the individual cells. By the way, if any of these cells have any kinks or dents in the bottom of them, they are not reusable. Okay. Well, if you like this content, please hit subscribe. Uh we offer hybrid and electric vehicle training here at Wever State University. See the link up here in the top of the screen for training. We also offer educational degrees, two and four-year degrees in automotive technology. and see this link up above here if you're interested in coming and furthering your education in automotive technology. All right. Well, thank you for watching and have a good