This article is intended to help builders working with the Tesla Model S and X battery modules (pre-Plaid). Please contact us at SHIFTev.com if you notice something we can change to make it more helpful.
PROTECTIVE PLASTIC CLAMSHELL DIFFERENCES
The 5.2kWh modules are the most common, often used for custom vehicle conversions and other applications. There are smaller modules that have fewer cells populated. However, the larger 6.3kWh modules have more cells populated, and in a different physical configuration. This prevents the protective plastic clamshells from smaller modules from fitting properly. The the vacuum formed plastic clamshells of different modules have strategically placed support structures and clearance tunnels. These tunnels protect the hair-size aluminum fusible links that carry current from each cell. If a portion of a top or bottom clamshell is an incorrect fit, or gets crushed, the fusible links may be compromised. Since cells and fusable links are positioned differently in the 5.2kWh vs the 6.3kWh modules, the clamshells are not interchangeable.
COOLANT CONNECTOR DIFFERENCES
The images show the coolant ends of the modules. On the right is a common 5.2kWh Tesla Model S battery module. Notice it has only two coolant connectors. This circulates coolant through a single ribbon-shaped coolant tube that contacts every cell once. The mating fluid connectors used by Tesla have O-ring seals and lock into position over the rib on the tube. However, the aluminum tubes on this module lend themselves to a simple hose and clamp solution that many hobbyists have used successfully.
The less common Tesla model S and X P100D module is pictured on the left. It contains more cells to create a 6.3 kWh module. Notice there are four coolant connectors because it has two separate ribbon-shaped coolant tubes. The four coolant connections are different than the 5.2kWh module. Without using the original connector as an adapter, it is difficult to make a reliable hose connection.
The stock P100D plastic fittings pictured are labeled VOSS PA66GF35. I was not able to obtain these from VOSS. They may have been superseded by the VOSS 246NX series, which has a differnet body, but appears to have equivalent seal and latch dimenstions. Be aware that the plastic connector part# does not assure what the O-ring type (material) is. I assume the stock O-rings on the VOSS PA66GF35 pictured above are EPDM because Voss specifies this for Coolant. Other O-rings available from Voss for this connector include NBR and FPM for Diesel and Biodiesel respectively. On 10/13/2021 I requested VOSS to confirm if the PA66GF35 with EPDM O-ring is functionally equivalent to the 246NX series (90-degree elbow) with NS12, NW8 with EPDM o-ring, but received no response. There are other important details about this type of fitting in the VOSS 246NX Assembly Instructions. But otherwise pursuing Voss USA and Voss Germany was fruitless.
After a great deal of searching and communicating with others on this, my search lead me to the parts pictured below.
The white latches are all shown in a "clamping state" that allows the two black clips to spring inward over the aluminum collar on the Tesla 6.3kWh Module. Pressing the white latch so its legs extend past the connector (a 5mm movement) causes the black clamping hooks to expand enough to remove the connector, but not far enough to break. With a light coating of O-ring grease, I was pleasantly surprised at how well they fit the modules.
The fittings are intended for use with a high-pressure hose, but a standard hose and clamp could be used if your application has the room for clamps. Two advantages of using the high-pressure hose are that it negates the need for clamps, and it won't collapse if you plan to draw a vacuum on your system. Disadvantages include its rigidity, requiring a minimum radius of about 10mm. Otherwise, it may kink. The biggest issue with this may be when routing inside a tight custom battery box. Also, the hose can't be assembled onto the connectors by hand. A special tool is needed because it takes a lot of force to assemble. Nice tools for this can be purcased, but I made the orange 3D-printed tool to load into a standard caulk gun.
Part source that we used: