Transportation: The large dead weight of EV batteries

The 2020 Honda Fit (using ICE) and the 2020 Chevy Bolt (EV) are nearly identical in capacity and general specifications – except for one very notable item:

2020 Honda Fit – image from Honda web site

2020 Chevy Bolt EV – image from Chevrolet web site:

The two cars are amazing similar with nearly identical cargo space, with or without the back seats up or down. The Fit includes a spare tire, the Chevy Bolt does not.

The biggest difference – the price and weight of the vehicles.

  • The 2020 Honda Fit starts at about $16,000 and weighs 2,522 to 2,648 pounds depending on options and version.
  • The 2020 Chevy Bolt EV starts at $37,000 and weights 3,563 pounds.
  • A Tesla Model 3 weighs over 4,000 pounds.

The Bolt EV weights almost 1,000 pounds or 38% more than the Honda Fit.

Why? The battery. The energy density of EV batteries is very low relative to gasoline. EV makers have to use large batteries to achieve a range of 200 to 300 or more miles.

When we consider the overall energy efficiency and emissions of the two vehicles, we should note the inefficiency of carrying nearly 40% more weight for a small reduction in lifetime emissions:

Update: I wonder what impact the heavier weight of EVs has on roadway surfaces? Weight has long been considered a major factor in the degradation of roadway surfaces. If we transitioned the entire automotive fleet to vehicles weighing 30-40% more, what effect does that have on roadways and what are the costs associated with those effects?

Compare the BEV (with gray bar height at top) to ICE, at far left. EVs do not have zero emissions (except during their operational phase). Total life time emissions are slightly less than a comparable sized ICE vehicle. In the above, we have compared two nearly identical vehicles in terms of physical size and interior space.

EVs would be far more efficient if it were not necessary to carry around so much additional weight for the batteries. We do hear of battery improvements (today I read of a tech that increases capacity by 20%-50%) but progress remains incremental, not revolutionary. Battery technology is very complex.

I really like the Chevy Bolt EV and it is the EV I would buy if I were buying today.

But, I already drive a low miles (30k) 2015 Honda Fit. Because the Fit has low miles it does not make sense for me to replace it with an EV. The best thing I can do for the environment is to keep the vehicle well maintained and drive it as long as possible as it is already considered a low emissions vehicle. “Repair, Reuse and then recycle” is the best environmental strategy.

Our State government wants to alter the cost equation by adding a carbon tax or “cap and trade” measure to encourage migration from an efficient ICE vehicle to an EV (at twice the price), with little benefit in lifetime emissions. As long as you ignore details, the State’s proposed tax makes sense – but once you look at the details, its insanity.

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