The blog for conversion of vintage BMW 3.0 CS coupes to Tesla powered electric vehicles
The Transplant is Successful
Get link
Facebook
X
Pinterest
Email
Other Apps
-
I've successfully transplanted all the components from the donor Tesla Model S into my 1973 BMW 3.0 CS coupe. The last organs to be inserted were the 10 battery modules up front. Now, all 14 batteries are in place, the motor, inverter, and differential unit is installed, the iBooster is operational, and even the Tesla electric air conditioning compressor is in place.
Tesla drivetrain fully installed
I slid in all the batteries, wired them all up, and made some cooling manifold mounts. After failing to keep my cool previously, I rerouted all the battery cooling lines in parallel using a couple 10 port manifolds so the box is all ready to be connected to the radiators. Once everything was in place and hooked up, I installed the acrylic skin and put the box on the winch.
Ready for installation
All wired up
Cooling hoses all connected
Needs a small adjustment to get the strut bars to fit
No extra room on the right, just enough for the A/C hoses
A perfect fit
No extra room on the left
I was able to lower the battery box into the car quite easily, all my myself one evening. It went in like butter. There's no extra room in the engine compartment but everything fits like it should (See below).
As you probably know, I'm not converting just one BMW 3.0 CS coupe to Tesla power but two. One for me and one for my son-in-law, Alex. In fact, I'm involved in a third project for a customer as well. Brett Perkins at P3 Conversions is handling that build and I just consult a bit but I thought it would be interesting to compare how each project has tackled similar problems in different ways.
As mentioned previously, careless treatment of the Tesla battery modules can be catastrophic, leading to fire or other failure. Therefore, it is important to monitor the state of the cells to assure they are in proper temperature and charge or discharge. To do this, a Battery Management System (BMS) is required. I'm using the popular Orion BMS 2. The BMS protects and monitors a battery pack by monitoring several sensors and using several outputs to control charge and discharge into the battery. The BMS measures inputs from cell voltage taps, a hall effect current sensor, and thermistors. Using the programmed settings, the BMS then controls the flow of current into and out of the battery pack by broadcasting charge and discharge current limits via the CANBUS to the OnBoard Charger (OBC). During and immediately after charging, the BMS will balance the cells using internal shunt resistors based on the programmed settings.
My priorities are all wrong. The car still needs a restoration and at the moment isn't even moving under its own power but I got side-tracked. In my defense, this all started over two years ago, when I had more momentum on the project. And it isn't uncommon for auto restoration projects to start with parts accumulation. Often they end before completion but I'm hoping that's not the case here. But I digress (again).
