Tearing Down Tesla: Comparing Secrets of Tesla and Other Leading EVs

Calling all automotive engineers looking for objective technical information about today’s leading electric vehicles (EVs).

This post kicks off a series of articles that will compare notable aspects of leading EVs. From OEM assembly time to suspension and from battery cooling systems to HVAC ducting and venting, this series will cover a lot of ground. Most importantly, it aims to offer knowledge that’s interesting and valuable to today’s engineers … with data points that support our findings.

We used our proprietary Design Profit software for all of our teardown analysis. It enables the teardown team to document each part, how it is installed in the vehicle, as well as how it’s assembled in each subassembly. With this data, we’re able to reverse engineer the assembly process for the given vehicle. More information about the software can be found here: https://designprofit.com/

With that said, here’s the first post ….

Did you know that the BMW i3 has a serviceable battery pack while the Tesla Model 3 doesn’t?

Background: The BMW i3 has a serviceable battery that can be lowered from the vehicle by removing the pack’s mount bolts located on the exterior of vehicle. Individual sub-packs can be replaced after removal of the cover and sub-pack fasteners.

The Tesla Model 3 battery pack was designed not to be serviced. It requires the removal of bolts in the interior and exterior of the vehicle to drop out the battery pack, as well as the removal of the vehicle’s seats and carpeting (to access bolts). The battery pack uses structural adhesives to seal and mount its cover and sub-packs, which does not allow service to open and easily remove modules for repair.

Insight: The advantage of the Tesla Model 3 non-serviceable battery pack is that it reduces the final assembly cost of the battery pack. The disadvantage is that if significant cell damage happens in the pack, then it requires a full swap of the battery pack.

Side note: based on the range for the Tesla Model 3 battery pack vs the BMW i3, in order to equalize, the BMW i3 assembly costs would be considerably higher than the current cost analysis.

Data:  The Tesla Model 3 uses three lines of structure adhesive bead and 78 fasteners, with a final assembly cost of $36.87 to mount the sub-packs and install the battery pack cover. The BMW i3 battery pack uses 120 fasteners, with a final assembly cost of $41.39.