As other automakers have launched competing electric cars, Tesla has managed to maintain an advantage in several key areas, including batteries.

Sandy Munro, of Munro & Associates, has been conducting a teardown of a Tesla Model Y. This time, he tackled the battery pack.

Munro's previous top-level conclusion was that the battery pack largely carried over from the Model 3, with some cost cutting measures.

Taking a closer look at the Model 3 battery pack, Munro also compared its construction to that of battery packs from other automakers. The Tesla battery pack consists of individual cylindrical cells glued together, with framework running between rows of cells and on the outer edges.

An alternative is the prismatic cell arrangement produced by Samsung, and used in the BMW i3. This places cells inside a box-like case, which is less effective at dissipating heat than the Tesla design, Munro said.

The Chevrolet Bolt EV's LG battery pack uses pouch-type cells, which connect end to end. These are the most expensive cell design, according to Munro, followed by the prismatic-cell configuration.

The Tesla cylindrical-cell configuration is much cheaper than either alternative, and quicker to manufacture, Munro said. It's also the most efficient "as far as space and weight is concerned," he explained.

What's more, individual cells in the Tesla battery pack are relatively low-voltage, so losing a handful of cells does not noticeably impact performance, Munro said.

Munro isn't the only one making EV teardown videos to show what's inside battery packs. You can get a closer look at the Bolt EV pack, or a view of the Tesla Model S, with a quick scroll through YouTube.

Teardowns like these have been done by consulting and engineering firms for decades, with key findings sold to automakers to help them stay competitive. In the YouTube era, they've also become useful resources to explain how things work—and in some cases, to provide critiques to the original automaker for how it might do things better.