Sceenario. Caught in traffic. heat on, wipers. How does the battery hold up.

Hi folks. A fella posted an interesting question on a non EV board and was wondering how an EV like the leaf would do in a situation where its cool put. wiper user, lights etc. Traffic jam situation etc. We will never be in this situation (or at least highly unlikely) so I couldn't answer his question. So lets say a new 30 KW leaf in a situation like this. Obviously you would have to get to a charge station after you got out of the traffic Jam but could you handle a few hours in this kind of a situation? Lets use the temperature of 32 degrees Fahrenheit. Zero celcius. I would love to hear opinions on this.

Thanks in advance.

webeleafowners said:

Hi folks. A fella posted an interesting question on a non EV board and was wondering how an EV like the leaf would do in a situation where its cool put. wiper user, lights etc. Traffic jam situation etc. We will never be in this situation (or at least highly unlikely) so I couldn't answer his question. So lets say a new 30 KW leaf in a situation like this. Obviously you would have to get to a charge station after you got out of the traffic Jam but could you handle a few hours in this kind of a situation? Lets use the temperature of 32 degrees Fahrenheit. Zero celcius. I would love to hear opinions on this.

Thanks in advance.

Click to expand...

I'm new here, so be a little skeptical of my answer:

Car is "on": about 400 watts
Lights: 150 - 200 watts
Assorted stuff: 50 - 100 watts
Heat: the elephant in the room. Anywhere from 1000 - 5000 watts depending on occupant choices. I thought that the newer models use a heat pump rather than straight resistance heaters, so that is another variable to consider.

IIRC LEAFSpy will report accessory load if you care to play around.

Short answer, not a problem. Here's a quick support:

assume heater draws 1kw (mine draws only 500 w in So Cal winters), that would consume 1kwh every hour. So it would take 10 hours of parking lot traffic to consume 10kwh of charge (~40 miles of range). In other words, you'd lose ~4 miles for every hour you're stuck in traffic.

Everything else draws only negligible amounts of charge and can be kept on.

In contrast, I've seen my usage go from 250 w/mile when driving at 60mph to 350w/mile driving at 70mph. In just 10 minutes (1mile / min), you've burned 1kwh of charge for just going faster.

The EV mantra to remember is: slow down if you're low on charge. That will conserve more energy and extend your range more than anything else running in the car.

The best way to deal with that scenario, if you are low on charge (otherwise it isn't a problem) is to put the heater temp setting on something reasonable (like 72F), set the ventilation so you get floor and defrost airflow, and lower the blower speed to the lowest or second lowest setting. With only a small volume of air having to be heated per second, the heat consumption is reasonable. If the car is a 2013+ Leaf, then setting it to Floor only, fan on the second lowest setting, and Partial Recirculate activated, will give the best overall result. (Although even partial recirculate may have to be turned off if the air is very damp.)

The most efficient speed for a Nissan Leaf is 12mph. So if your traffic jam is moving, but slowly, you'll probably actually arrive at your destination with more charge remaining in the battery than you normally would.

But if you think you'll be stuck in it for hours, I would turn off the heater. With that done, the Leaf will probably last longer than most of the ICE cars stuck along with it.

What different folks find tolerable as a minimal comfort level certainly varies considerably, but myself, I've found that at temps down to about freezing using the heated seats and heated steering wheel more or less eliminates the need for cabin heat. They draw considerably less power than the cabin heater (less than 100 watts) - http://mynissanleaf.com/viewtopic.php?t=10617.

Defrosting/defogging needs are a different complication - a good number of folks have done various modifications to minimize the power draw:

http://mynissanleaf.com/viewtopic.php?t=11412

http://mynissanleaf.com/viewtopic.php?t=20446

http://mynissanleaf.com/viewtopic.php?t=6751


Hope that helps answer the question!

garsh said:

...With that done, the Leaf will probably last longer than most of the ICE cars stuck along with it.

Click to expand...

Agreed. A friend was with a friend and while skiing in Tahoe, somehow the driver left the parked SUV engine running for about 6 hours and it burned a 1/3 of a tank that started full... There you have it. If they'd only had a quarter of a tank, well, AAA...