EVTV Tesla Model S Full Battery Pack Controller for EV Conversions or Energy Storage Systems (ESS)

This battery controller, Version 2, uses an Espressif ESP32 chip with Wi-Fi capabilities to monitor Tesla Model S Battery Modules. Broadly, it simulates the BMS management board in a full Tesla Model S battery pack to monitor each of the 16 battery modules in the pack by communicating with BMS boards mounted on each battery module. This controller also features two contactors and a current measurement sensor, along with software to allow you to communicate with up to 32 Tesla Battery Modules and control access to them.

This controller works with either the 6.3kW Model S/X Modules as well as the normal 5.2kW Model S/X that we have traditionally used! Note: the 6.3kW and 5.2kW modules can not be used together.

EVTV Tesla Model S Battery Module V2 Controller

We're back. When last we spoke, I had a cup of Tesla coffee. Several people mentioned that it never seemed to run dry.

I ran into a genie, and he said I could have one wish, anything I wanted. And I said I like Tesla and I like coffee. What can you do for me? So I'm thinking the new, you know, sports drink with a curry in it.

Well, he comes up with this cup, and it never ends. It's always full of coffee. No matter how much you drink out of it, you can fill it right back up and drink some more.

And they say it's good for a million recharges. So we have this one, and we have this one. And I actually, I just ripped off Tesla's logo, did a little magic in Photoshop, and I had some cups made up.

If you want one, we can work something out. Over here, with Danu, is our V2 controller, our version 2, the ESP32 version, of a Tesla battery module controller. It's not a BMS.

It actually talks to the BMS that Tesla designed, that's on the batteries. It's our most popular device, because people want to play with these batteries. Now, we sell the batteries.

We don't like selling batteries. Most people get batteries somewhere else, and they want to experiment, as we do here at EVTV. And this is the enabling box.

It lets you talk to the BMSes, and it manages two contactors. Basically, its job is to shut off the battery, if anything is out of line. Temperature, variance, voltage, a whole bunch of stuff.

We have devised these Raspberry Pi displays, and Danu came up with a very cunning idea, which I found out later, he actually stole from one of our customers. But he claimed it, and that's just as good. We have a lot of problems with people with Windows computers.

We've devised the most basic interface you can have to anything, and that is an ASCII text USB port presentation It doesn't get more basic than that, but I guess I may have lived too long. It's so basic, nobody knows how to use it anymore. It's pretty old.

And that's okay, we can kind of walk them through it, unless it's Windows. I've got a long-standing thing. I don't do Windows product support, and they don't really do electric cars or solar.

It's kind of a gig I got worked out with Bill Gates. I just don't do Windows support. I spent the 90s, I spent the 90s teaching people how to hook up Windows machines to the Internet.

I authored the definitive guide on how to do that with Trumpet Windsock. Eventually they put it in the operating system, you didn't need to do all that. But man, I was worn out of doing Windows product support for like 10 years.

I don't do it anymore. I never want to hear about Windows. I went to six years of Linux, and then finally to Mac OS, because the Linux guys just would not accept drivers from any device unless they released the source code to it.

They had a religious dogma about device drivers, which is the most uninteresting thing in the world. Who cares? But they just wouldn't do it. So we don't do Windows.

So Danu simply downloaded CoolTerm for Linux into the display, and you hook it up to the USB port, and you can do all the stuff with the display, because people didn't have a Mac laptop or a Linux machine. They had a Windows machine from 2004. Which is getting back close to when I would maybe be able to help them, but I'm not going to.

So we kind of have done a lot of incremental improvements over time to that controller, and it is kind of our bread and butter. We sell more of those than everything else combined per unit. And so I asked Danu to put together a little video on how to hook it up and how to configure it.

And man, a star was born. Take it away, Danu. Hello, my name is Danu, and here I am at EVTV.

I'm the lead technician here, and today we're going to talk about the V2 that we sell and how to make it work. So let's start off with the V2 itself. We have the device right here, and if I show you, you'll see the on-off switch right here, a red LED for our negative contactor, a green LED for our positive contactor.

Now these two indicate when they're on that the contactors are closed. And over here we have a CAN port, which is a simple RJ45 port connection which you can use for a charger and also different other devices that we can show you later in the video. And over here we have the USB serial port and that is a type B connector that you can use to either get data from the modules that we have, Tesla Model S modules that we use to make the V2 work.

And so going over to the front of the V2, one of these ports, which is this black cable, is for the BMS that you will connect to the modules and we will show you what the ports look like afterwards as well. And then on this side we have a 12 volt input. So these V2s are built for voltage ranges from 24 to 48 volts.

And if you're planning to use these V2s for modules that are more than one in series or two in series, which would be more than 48 volts, you would need to use a 12 volt input to supply 12 volts from outside. But most of the builds, like this one right here, is a 48 volt system with two modules in series which you will get 48 volts maximum. So that is perfectly set for these builds.

And then following these wires you have a red outside for a positive input and on this side you'll see we have the current sensor that we have put outside just for being easier for the heat to dissipate. And then this wire and then this metal piece right here is custom made for Tesla Model S the plate basically where it will be on top of the battery and that will connect directly to the current sensor. And then going over to the other side, I think we'll have a picture of this to show you better because I can't turn this all the way around.

So on the left we have the positive side again for the output. On the right we have the negative which is black. And then on the top here you see the charge enable.

Again a two pin connector which we will send with you with the V2. And then another two pin here which we'll send as well for the heat enable. And these are ports that you can customize.

This can enable and disable a charger and this can enable for the batteries. So basically with lithium ion batteries you don't want to charge them when they're cold or discharge them either or even with cooling when they're too hot. So that's why we have these ports.

And we use them for different purposes in our power safe as well to enable the grid and stuff like that. And you can use it however you want because we send the software as is and if you look into our PDF you can see how to customize them how you want. So moving on.

Going on to the batteries and the connection side. So I told you this is the BMS connector. So what we have here is an example of four module setup.

And this is two in series. You can see we have a 70 millimeter I'm losing the name right here. What do you call this? Braided battery strap.

We have one up here that will connect them in series and then what you see here is a copper U-strap that will connect them in parallel. There's one on this side and one on this side. And that basically gives us 48 volts because there's two in series but going down we have two in parallel so we'll get 48 volts but we can get more power out of this.

Each module is about 5 amp hours and right here is a 20 amp hour setup. And this is about you can't really get a lot of it but this is our V2 test bench so this is plenty enough for what we try to do. So just for four modules what you would need is a four port terminating harness.

So what you see here is the opposite end of this BMS connector. I'll show you it just clicks just like that. And this runs from here from module to module and it ends right there.

So this is a four module extension. So this starts with the same just like this but if you follow it it will come and end with this which looks just like the male end of the ESP32 I mean the V2 male end. So what happens is you would just connect this to a terminating end and now you can connect four more modules and this is how we do it for our PowerSafe we just have four more of these to connect 20 modules in total and now let's say you have you don't have four but you have six so that's where you would use a terminating two module harness.

So this just has that female end right here which again you will connect to the male end of this and then you get two modules and then you have the four right there. So that's one module. So how would you connect one module? Simple.

You would take a two module harness and you would use a shorting plug which we also sell on the store and you would use just this small piece to plug to the end of a two module harness and that basically renders just this one usable and you connect this to one module and then you can connect the male end of the V2 and bingo So the way these work is the data goes all the way to the end and comes back so you should make sure that the shorting plug is always at the end of it and we use this to test modules and also to when we want to bring them down to a certain voltage or to bring them up to a certain voltage by charging we just use a shorting plug and put it on one module so yeah so you can have these in 24 volt setups by just having one module or you can have them in 48 volt setups by having them side by side in series Let's go ahead and plug this in I guess so we can show how to wire it up So this bolt this usually comes with the Model S battery modules itself but if not you can purchase you can use a 13mm wrench or you can also use a half inch wrench nut driver is the easiest way to do it and I mean we can use wrenches or nut drivers and I'll show you how to tighten it right here you make sure there is nothing in between the surface of the the surface of the terminal lug and the surface of the battery here we have a copper strap you can put them together but you make sure that they are clean and then you put this put the nut in and then you tighten it and now the key thing here is to make sure that you can tighten it and once you are done tightening it you can't move this if you observe I can't move that lug at all and what that does is make sure that this has a good connection to the battery and that's what happens so this if there was something in between the connection or if this was ever so loose this will warm up whenever you are using current through it and that will be the first place to fail and it can be catastrophic when it does and so that's the positive side over here let's go over to the negative side so we have the custom made terminal that we have that falls right on top of the Model S battery module to fit the screw in it's just smooth and what you do is just put the screw in through there again socket wrench what do you call this James? nut driver I forget names and tighten it down just like that again same idea make sure it doesn't turn that way you know it's tight and that's how you tighten the input sides of the battery then don't forget this because without this if you try to switch on the V2 right now it won't really come on because it's not communicating to the batteries so when you connect it in that's when you can switch on the V2 and get it to work and another thing here is if one of these connectors are loose it won't complete the communication circuit so again these LEDs won't come on because the contactors won't close and they won't communicate to the battery so you need to make sure all the modules are good and that's why we use the 2 port harness with a shorting plug to make sure each individual module is good before we try to try all of them together and what else over on this side we have the same 3 8th hole which perfectly fits for an M8 bolt and that's the output positive and the output negative and this you can wire up and you can use it to however you need and going over here you can see a TCCH charger that we use and it's wired into these terminals already so we can use it to test the charging and also discharging we used to have an inverter there but it's not there anymore which we use to test this as well and that's just a few basic ways of setting up how to use the V2 as well as on how to do the setup where you get the display to work and we will show you that in the following up video which we will use the serial port right here and to communicate with the V2 to get it to set up on the WiFi so you can communicate wirelessly to our display stay with us so this is a quick tutorial on how to set up the smart WiFi router the mini smart router it's called a GLiNet mini smart router and we are going to use this to get communication between the ESP32 V2 and the display so let's dig into it and this is a very light package it's a very tiny router actually if you look in right here so I'm going to set this up right here and it comes with a USB cable so this uses 5V about an amp of power so very tiny I don't know how much the range would be but I'm pretty sure I could find it if I look for it can do up to 300 Mbps so if you look back here this already has a set SSID and a password so what I'm going to do is change this into what I want it to be and to do that I need a computer so instead of connecting this to the computer I'm actually going to connect this to the power bank so I can make it truly wireless so I'm just going to give it 5V from my power bank and we have the LEDs lighting up so now if you look into the computer I'm going to start to see the Wi-Fi if it shows up pretty soon searching so right now this computer is connected to EVTV but what I'm going to try to do is connect it to this GLiNet mini smart router there you are so it's called the GLAR300M619NOR so I'm going to connect to that and the password on this is set to default as goodlife double O-D-I-L-I-F-E confirm that and join in so I'm going to connect so I don't have Wi-Fi internet access on this but I'm using it as an AP and actually I found on the instructions that I can change this between router mode and bridge mode so bridge mode would be where the router will be transparent but that is not what we want to do here we're trying to get this as a router to communicate between the two devices so I'm going to keep it at router mode which means there's a switch down back here that has to be towards the left which is where it is right now so I'm going to leave that as that is and now that I'm connected I'm going to go into settings and change the SSID and password so what I need to first do is get the IP address of the router which I would know by the top of my head but I don't so I'm just going to get in there and it says 192.168.8.1 so what I'm going to do is go into the browser Safari over here 192.168.8.1 over here and it gets me into setting up configurations on the router I'm going to select English it's asking me for a time zone I'm just going to select America there you are and I guess we'll be on the Chicago timeline next and then password so this is just a password that we would need to change settings on here so I'm going to type in Safari don't use that just going to type a simple password Capital M-O-T-O-R Motorwork and try that again M-O-T-O-R-W-O-R-K-S this is just so that this would stop other people from getting in to change the password but it's not that important so since I'm connecting through Wi-Fi it says I would need to change the password again but all I'm trying to do is get into the system which I just did and now I'm going to change the settings on the hub itself so if I look here I have the wireless status saying it's online and the device that is connected to it right now which is this computer so I'm going to change the settings and here you go that's the SSID so I'm going to change the SSID into Wi-Fi hub and then change the password into Motorworks again M capital and everything else in simple case submit it so it's going to update it online that can cause this to disconnect from the Wi-Fi but that's basically it so now if I refresh the page you can see I'm already disconnected from the internet so if I re-scan I have Wi-Fi hub over here and the password is M-O-T-O-R-W-O-R-K-S join and do we have a connection? yes we do and now if I refresh the router page again I am connected to this and now you can see SSID is set to Wi-Fi hub and the password is Motorworks so using that information now I'm going to set up the ESP32 and the display so here we have the V2 connected to the battery modules on our test bench already and so I'm going to walk you through on connecting this to the Wi-Fi our Wi-Fi now is this portable very tiny hub that we just talked about connecting on how to set the SSID and password so I'm going to walk over here and connect the display to this Wi-Fi hub which does not have internet access but it's still just a hub and this is all we need to communicate between the two so getting the box this is the box that you get the display in and this comes in the V2 itself in the big V2 box itself opening it up we have this white box which the display will be inside and then we also have this power cable inside this box which I have already connected to 120 AC so I'm going to boot this on there's a switch right here and it's booting up and while it's booting up we also have an HDMI cable which we won't be using for this and a wireless keyboard which we will be using for this so I'm going to take this keyboard out also we will only be using this keyboard for a very short time so you don't have to take this out if you have a USB keyboard at home you can use that as well you would just simply plug it in to the USB port back here so this wireless keyboard which is pretty neat has a USB here at the back so you need to take this USB connector out and then simply plug this receiver into the back of the display just like that and then now the display is booted up with the BMS display I'm going to switch this keyboard on we have power so I'm going to set up the Wi-Fi on this to connect to this hub that we have over here so this is going to be a little tiny but I'm going to hopefully show it step by step we can't unfortunately get this on a bigger display because this is still not connected to the Wi-Fi so to do this I'm going to go to the gear icon which is our configuration setting and right now you can see there's no data in here because this is not connected to a V2 controller right now so I'm going to press the left arrow that will take me to the different page on configuration setting and over here there's a button for exit which will take me so I have the keyboard in hand I have the display and now I can move the mouse around with the touchpad and I also have a keyboard for input so what I'm going to do is we have the Wi-Fi icon here on the top so I'm going to move up there click that and if you look we have Wi-Fi hub here we can get a zoom in on this onto the display and here you can see Wi-Fi hub is it visible? perfect so what we're going to do move the mouse down click Wi-Fi hub and now it's asking for the password so the password which we just set up in the previous video is MotoWorks with capital M so M-O-T-O-R-W-O-R-K-S so to confirm that I have it right I'm just going to say don't hide characters and I click OK and now you can see the Wi-Fi is trying to boot to connect and what we're doing is connecting it to this small hub right here and we have a connection so again we do not have internet access we just have a hub that is communicating between the display and the ESP32 so now that this hub is connected I'm going to set up that communication on the big display as well so I can explain the rest of the steps and how we connect the ESP32 to this Wi-Fi as well so to pick it up from where we left off so I have this connected to the hub and now I'm going to try to set up the VNC on our ThinkPad Windows 10, Windows 8 actually the old laptop so what we're going to do here is first figure out the IP address of this device and that can be done by hovering the mouse over this Wi-Fi icon over here and it's pretty tiny text but what I'm seeing if I can get it it says configured 192.168.8.126 so that IP address is basically telling what this device is logged into and this Raspberry Pi already has a VNC server built into it that is how we ship it out so all you would need is a computer with a VNC receiver which is available to download free of charge and Jack will add to this description as a link so when you have that downloaded over here on this screen when you open it up it will ask you for an IP address to connect the display onto so what I'm going to do is make sure that this is connected to the same Wi-Fi hub because that's when the Wi-Fi when the devices are connected to the same hub VNC basically allows you to mirror this display on a different screen so I went ahead and already connected this computer to this small Wi-Fi hub already same procedure it says ID, password, connect so now that I have the VNC viewer on this computer I'm just going to type in the password type in the IP address excuse me so I need it to be 192.168.8.126 and once I've typed the IP address in I hit enter and then now it's asking for a username and password which the server we set up we set up our own username and password and that's also available to be found on the end of our manual but the username is xpipi and the password is evtv all in simple case evtv.