Tesla Semi Technical Images Emerge

The battery system appears to consist of nine large modules.

By: Mark Kane

Jan 2, 2023 at 1:41pm ET

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A few weeks after the Tesla Semi delivery event, an interesting set of technical images emerged, throwing a little bit more light on the electric truck.

The images, shared by Tesla "data miner" green (@greentheonly), comes from the company's online Parts Catalog, and presents various subsystems of the vehicle.

Let's take a look at some of those drawings, starting with the Tesla Semi battery system, which as we know is rated at around 1,000 Volts.

As it turns out, the battery of the Semi is located below the cabin and consists of nine large battery modules, although not all of them are physically the same size, as the three in the middle appear to be bigger.

As we know, the 500-mile version of the Semi is estimated to have somewhere around 850-900 kilowatt-hour (kWh) of battery capacity (based on energy consumption numbers). There is also a 300-mile version in the pipeline, which potentially will get a lower number of battery modules.

The next important thing is the tri-motor powertrain at the two rear axles (2nd and 3rd). The first one is called "Torque" axle and it has two electric motors. The second one is called "Efficiency" axle as it has only one electric motor, which is optimized for driving at a mostly constant, highway speed. As we understand, the Torque axle is engaged (physically) only when there is a need for it (significant load or acceleration).

According to Tesla, the electric motors in the Semi have carbon-sleeved rotors - just like in the Tesla Model S/Model X Plaid introduced in 2021 (see the presentation of the front motor and two rear motors here).

front axle (Torque) with two electric motors

rear axle (Efficiency) with one electric motor

An interesting thing is the cooling system on-board Tesla Semi, which indicates a big block at the vehicle's charging inlet. Let's recall that the company intends to fast charge the Semi at more than 1 megawatt (MW).