Objective Reporting
If you read my article The Four Inherent Advantages of Electric Vehicles you might’ve thought I was just a Tesla acolyte who serves for the glory of Elon Musk and has a shrine to Rimac in my room.
WRONG.
On the contrary, I am a very reasonable human being, and on that basis I am going to inform you about what totally sucks about battery-electric vehicles.
CHARGING.
Okay, yes, there are other issues like consumer cost, lithium mining, high repair costs which means high insurance costs, but that can all be dealt with fairly quickly through economies of scale and improved manufacturing processes.
Charging, however, at least with current battery technology, is a physics problem, not an economical one. Typically, these issues are much harder to overcome.
You may be asking yourself, “Okay, but why is charging such an issue and why is it more difficult to fix as opposed to these other economical factors?”
Excellent question, and for the answer I have turned to the internet and science.
Science and Stuff
The U.S. Department of Energy has an excellent animation explaining how lithium-ion batteries work. Basically, batteries have two sides, an anode and a cathode. It’s not necessarily important which side is which, the main point I want to get across is that as a device gets used, lithium ions travel from one side of the battery to the other through an electrolytic substance which releases electrons that are the source of the electrical energy.
That’s how a battery is discharged. Recharging is the same process but in reverse. This means that if batteries were only capable of recharging as fast as they were able to discharge, everything would take quite a long time to get to 100 percent.
The rate of recharge depends on the battery’s internal resistance rate. You might have touched your phone and realized how warm it was while it was plugged in—that’s the internal resistance. Because of this resistance, batteries can only charge so quickly, usually somewhere around ten times their discharge rate. That’s a massive oversimplification, but the point is that while we can charge batteries faster than we use them, exactly how fast is limited by the physics of the battery.
Why is this a problem for battery electric vehicles?
Mainly because all of us have grown accustomed to five minute fuel station stops. I guess you could say that our expectations are the problem, but even if we had no clue that a top-off could take four and a half minutes, would you still want to wait half an hour to charge your car?
However, most people rarely charge their electric vehicles all the way to 100 percent on a road trip. The reason is that the final 20 percent of a battery’s capacity requires almost the same amount of time it takes to charge from 20 percent to 80 percent capacity. This is due to the chargers dynamically altering its voltage and output current to prevent battery damage. The same thing occurs with your cell phone. In reality, a DC fast charger will get you back on the road in 20 minutes or so, and that’s if you have used the majority of your range.
Is There a Solution?
The reason that this is a problem is because the solution isn’t readily available or known. It’s going to take some massive R&D to find a battery that can accept the massive amount of energy needed to charge a 400-500 mile range battery in five minutes. Car manufacturers have alleviated the problem by introducing quick charging stations that operate at massive current levels, but even prior to hitting the dreaded final 20 percent the recharge time is relatively slow compared to ICE counterparts.
The reason for this slow-down in recharge rate has to do with the battery chemistry. Essentially, if the charger kept pushing energy into the battery at a fixed rate, it could damage the battery, shortening its life or ending in a Michael Bay explosion.
I certainly think that with enough research and many different companies striving to improve electric vehicles there will be a breakthrough in battery technology. Even now, unless you’re on a road trip, your vehicle is primarily getting charged at home while you sleep.
Final Thoughts
In my opinion, range anxiety is overhyped and people don’t realize how nice a 20 to 30 minute break every three to four hours during a road trip is. While I typically focus on getting to my destination as quickly as possible, my favorite road trips have been the ones where I took the time to smell the flowers, so to speak. Road trips are about the journey, not just about where you’re trying to go. To that end, next time you’re driving across the country, plan an extra hour to enjoy the in between just a little more.
