King of EV Range

Now entering, the Lucid Air

Lucid Motors has revealed that its insane 517-mile range is achieved on a 113 kWh battery pack — showing its efficiency expertise.   

I am writing on September 9th, 2020 about three hours prior to Lucid’s big press conference to announce the release of the Lucid Air.  There are rumors that the electric vehicle could be the new standard.  Not only will it have the longest range for an electric sedan, but it could be quicker than the Tesla Model S Performance. 

Update September 10th:  In a ¼ mile drag race, the Air beat the Model S Performance with a time of 9.9 seconds.

In the 9/9/2020 announcement, it was confirmed that the Air will have a 113 kWh battery pack with a range of 517 miles.  An efficiency of 4.57 miles per kWh is by far the most efficient vehicle.  The Tesla Model S Long Range Plus with the most recent software upgrade has a range of 402 miles.  Therefore, its 100 kWh battery pack yields an efficiency of 4.02 miles per kWh.

But let’s make a fair comparison, because the Model S uses smaller 18650 Li-ion cylindrical cells.  The Air will use the same 21700 cylindrical cells that the Model 3 and Y both use.  Both the Model 3 and Y have 75 kWh battery packs and pack ranges of 322 and 316 miles, which correspond to efficiencies of 4.29 and 4.21 kWh.  In the table below you will see the simple division of range divided by battery size.

If the cells are the same, then the efficiencies must be in the remainder of the engineering.  The battery pack voltage of the Air is 924V compared to 350V for the Model 3 and this presents a significant difference.

Let’s reference the basic power equation - V*A = W.  Battery voltage multiplied by current amperage yields power (watts).  This can provide us an indication on the electrical current needed to supply the battery’s power output.  

As you can see Tesla has made improvements to reduce the current needs of the Model 3 and Model Y, but the Lucid’s current demands are much lower.  

The battery pack amperage of 122A is significantly less than that of the Model 3, which would mean that less current is needed to supply the power needs of the vehicle.  This could correspond to the use of smaller (higher gauge) diameter wires to reduce weight.  Or, if Lucid decided to use the same gauge wiring as Tesla there would be less heat generated.  Lower heat generation results in improved efficiency due to less resistance.

Now let’s have a look at the battery configurations of the Model S, 3, Y and Lucid Air.  

There are some unknowns that are critical in determining how Lucid is handling the significantly higher voltage battery pack.  The Model S engineer that designed the Lucid may or may not be using a novel configuration.  For simplicity, we can speculate that the Air may use a similar configuration to the Model S.  

If he designed a similar parallel to series configuration to obtain the total 924 volts, then each module would be 57.75 volts strung in series.  I have not been able to find the parallel to series configuration for the Model 3 or Y, but since the 21700 has higher energy density, and is larger there will be a fewer number of cells.  A 21700 is about 50% larger by volume, so in order to squeeze the same volume into a configuration used in the Model S it would require the use of fewer cells.  Therefore, we can speculate that the Lucid Air will have in the range of 4000-4500 cells, which would be similar to the Model 3 and Y.

Finally, module voltage will most likely be higher, which would suggest that more cells are tied together in series.  

I will continue to dive deeper into understanding the differences between Tesla and Lucid as time goes on.  It is certainly interesting to try to piece together how Lucid’s lower current battery configuration is so unique.