It’s Good to Have an Engine This Week

The nice thing about engines – well, one of the nice things about them – is that they work just as well when it’s bitterly cold as they do when it’s warm. Well, assuming you have a healthy battery to start the engine.

As most people know, bitter cold weather is very hard on starter batteries. More finely, bitter cold makes it harder to start a car, because the battery’s ability to crank the engine over diminishes as it gets colder. How much is that, exactly? Well, at 32 degrees, a fully charged battery loses 20 percent of it’s cold-start cranking power. If it’s zero outside, the loss is 50 percent. That’s why a battery that’s a little aged and weak to begin with may not be able to start your car’s engine at all when it’s bitterly cold out.

Most of us have found this out – the hard way – at some point in our lives.

EV owners are probably finding it out right now. The same physics that negatively affect an engine’d car’s 12V starter battery also negatively effect an EV’s battery pack. But the consequences are different and more serious.

Let’s begin with the engine’d car. Once it – the engine – starts, it will run as it always does. If may even run better, because cold air is denser than warm air and that can increase power and efficiency (it is one reason why turbocharged cars often have intercoolers). It will certainly run as far as it would have if it weren’t cold out. If you have a full tank and your car normally goes 400 miles before the tank runs to empty, you will be able to drive the same distance when it’s cold out. No one worries about the range of their engine’d car, in other words – unless of course they forgot to fill up and the tank is close to empty already.

You can also crank the heat – and defroster – without any effect on the engine’d vehicle’s range because use of the heater and defroster uses heat generated by the running engine, a kind of freebie you get with an engine’d car in that it doesn’t cost you anything (range-wise) to use the heater vs. not.

The owner of a battery-powered vehicle, on the other hand, has at least two problems on his hand when it is very cold out. The first is that even though his device will turn on, it will not go nearly as far; see that part about charge loss resulting from very cold weather. EVs do have what’s called a thermal management system that keeps the battery warm while it’s cold out, but that burns electricity – which depletes the battery’s charge. You can avoid that loss by plugging the EV in while it’s parked – but only people who have a place to plug in (such as a garage or single family home/townhouse) can do that. If they don’t – and leave the EV out all night in the cold – they may discover they have lost 20 or 30 miles of range just from sitting in the cold overnight.

But that’s just for starters – pun intended.

As you drive – a device – in very cold weather, you will notice that it bleeds charge (and so, range) much more rapidly. Precisely because it is cold. The battery is doublewhammied  by environmental factors – the cold – and by the draw on the weakened battery by the thermal management system, which burns electricity trying to keep the battery warm. Since you can’t plug in and drive at the same time, you find you can’t drive nearly as far as you might have been able to when it was warm outside.

It gets worse if you use the heater – which uses electricity to keep the car’s cabin warm.

In very cold weather, an EV’s normal driving range – in warmer conditions – can plummet by 40-50 percent. If you started out with a less-than-fully-charged battery, you may not be able to drive far enough – as to to a place where more charge is available. Or where there is heat – so you don’t freeze to death in the cold.

Some will remember the blizzard that snowed-in much of the Northeast a few years back, at the very beginning of EV Fever. It cured that right quick as people found of what happens to an EV’s range when it is cold out and what can happen when you run out of range before you can reach a place to get more (or get warm).

You might not even be able to charge your EV if you do get to a place to charge it – i f the charger isn’t working. That happened during that blizzard, too. It is probably happening this week as well.

Meanwhile, if you find yourself caught in a blizzard in a car with an engine – and a full tank of gas – you’ll be able to stay warm for a day or more (if need be) by running the engine, to create the heat. An EV might be bricked – and if it’s very cold out, you might be, too.

Whereas even if you have a dead battery – in a car with an engine – all you need is a set of jumper cables (and another car to jump-start yours) and you’re good to go.

There’s no jump-starting a croaked EV. And even if it were possible to do that, you’d only be able to drive it as far as the cables reach.

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