A larger format, low C rate battery would significantly cut costs, and weight.

Maybe Tesla’s new “Megapack” fits into the puzzle as well?

We just published an article on the Tesla Pickup Truck and in that article estimated the pickup’s battery size at 200 kWh’s and its motors at 600 HP (447 kw), for a paltry C rate of only 2.2; much lower than Tesla’s sedans.

The Tesla SEMI truck also has a low C rate. Our analysis of the semi truck had four Model 3 motors for a total of 1080 HP (805 kw) and 900-kWh battery, putting the C rate for the SEMI truck at only around 1. Both the pickup truck AND the semi truck have low C rate (power) batteries.

Here’s a figure that shows the effect of format size and electrode thickness on cost (ref):

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Effect of cathode thickness and battery size on cell costs

The graph shows the effect of electrode thickness (C rate) and battery size on cost and it shows a huge effect on costs in the neighborhood of 20%. Thicker electrode coating gives us lower C rates just like in the semi and pickup.

We have the semi and the pickup that could live with a lower C rate, larger format battery. We also have Tesla’s new, secretive “Megapack” for huge power pack projects (ref) and it turns out that power pack installations also have a low C rate (ref).  In our opinion, it justifies a new line of batteries for the Gigafactory=larger format, low C rate batteries.

Big win in the cost, weight and energy density departments.

I know it’s a bit far-flung to predict another increase in format size. We’re pretty close to production on the semi. A bit late to be starting on a new battery design but Tesla’s future battery designs are a closely held secret just like the “Megapack.” Could be that they have a large format low C rate design already in development?

A long shot for sure but interesting food for thought nonetheless.