Tips To Keep Your Electric Car’s Battery Healthy In The Record-Breaking Heat Wave
Yesterday, temperatures across Arizona, Nevada, Utah, Colorado and California reached record-breaking highs, making even the most normal of everyday activities unbearable for all but the most hardened of heat-loving Americans.
Like humans, electric car battery packs prefer moderate temperates rather than extreme tropical ones, but with the heat wave set to increase its intensity and widen into northwestern states like Oregon, Washington, Idaho and Montana, what can you do to keep your car’s battery pack happy in unbearable weather?
Avoid Extremes of Use
Just like any other battery pack, passing current in and out of your car’s battery pack will warm it up. The higher the current passing through the battery pack -- either in or out -- the quicker the pack warms up.
It’s worth noting too that as the battery pack reaches 20 percent full or less, its cell voltages start to drop dramatically. Since electrical power equals voltage times current, the current drain on the battery pack will increase as the pack voltage drops to maintain the power levels demanded by the car. This will in turn heat your car’s battery pack up—not exactly what you want when it’s already triple digits outside.
To keep your battery pack as healthy as possible and as cool as possible, it’s best to avoid heavy acceleration and running your car down to a low state of charge.
As we’ve just explained, passing high currents through your car’s battery pack will cause it to heat up far more quickly than passing low currents through it.
Since the CHAdeMO quick charge and Tesla Supercharger stations rely on extremely high current flows to quickly replenish the battery packs on cars like the Nissan LEAF or Tesla Model S to 80 percent full in under 30 minutes, think twice before using them when the mercury is reaching for the sky.
The same is true for 100 percent or ‘range’ charges in hot weather. As a battery pack reaches a full state of charge and its internal resistance rises, it becomes harder and harder to push electrons into the battery. In turn, this puts additional stress on the battery pack and increases the rate at which it heats up.
Consequentially, if you know you only need an 80 percent charge to reach your destination, setting your car to stop charging at 80 percent will put less strain on it and help it stay healthy in hot weather.
With the sidewalks in some cities hot enough to give pedestrians second degree burns, you need to make sure that your car gets just as much shade as you do.
Where possible, park in the shade out of direct sunlight, as this should help your car’s battery pack stay cooler than it otherwise would. In addition, you’ll find your car far more pleasant to return to.
Keep Your Car Plugged in
While some cars like the Nissan LEAF and Mitsubishi i rely on passive forced air cooling to keep them cool in hot weather, others—like the Tesla Model S, Chevrolet Volt and BMW ActiveE—use sophisticated thermal management systems with liquid coolant.
By closely monitoring the pack temperature, these fully-automated systems work by pumping refrigerant around the battery pack to keep them operating at peak efficiency. If your car is not plugged in, they will use some battery power to keep the pack cool. If your car is plugged in, they will generally run from mains power.
If your car uses an active thermal management system, it’s a good idea to keep it plugged in whenever possible in hot weather, to maximize range and keep the battery pack as cool as you can.
New to EVs? Start here
What Is An Electric Car?
Before we get going, let's establish basic definitions.
A Quick Guide to Plug-in Hybrids
Some plug-in cars have back-up engines to extend driving range.
Electric Cars Pros and Cons
EVs are a great solution for most people. But not everybody.
Seven Things To Know About Buying a Plug-In Car
A few simple tips before you visit the dealership.
Federal and Local Incentives for Plug-in Hybrids and Electric Cars
Take advantage of credits and rebates to reduce EV costs.
Eight Factors Determining Total Cost of Ownership of an Electric Car
EVs get bad rap as expensive. Until you look at TCO.
Quick Guide to Buying Your First Home EV Charger
You'll want a home charger. Here's how to buy the right one.
Electric Car Utility Rate Plans: Top Five Rules
With the right utility plan, electric fuel can be dirt cheap.
The Ultimate Guide to Electric Car Charging Networks
If you plan to charge in public, you'll want to sign up for charging network membership (or two).
Eight Rules of Electric Vehicle Charging Etiquette
Thou shalt charge only when necessary. And other rules to live by.