[Scally]

Winter kills range, we all know that. But why exactly? Is it just the battery temperature and the use of the heater and demister? And if so, what about long distance trips - with multiple rapid charges?
I'm interested in heading from Scotland to Cheltenham at Christmas - a 350 mile trip I have done three times this Summer in my Mark One 2013 Leaf. So what I wish to ask is - does the poor initial performance starting from cold improve as the battery is repeatedly warmed up over multiple rapid charges? Has anyone ever measured this?

 

[bryand]

Last year I came back from Devon with the car at 2°C. I stopped and gave it a rapid charge as soon as I could, and that improved the battery performance (and range per charge) no end. Battery is best at 5-6 temperature bars.

 

[Scally]

Great, thanks for the tip. It's a real challenge heading over the big hills at Beattock summit and then Shap Fell, and one time I nearly lost the plot and chicken-shitted off to Leadhills for a Type 2 charge top up, being unconvinced that the regen would work. But as any experienced EV driver knows, you can pick up an extra ten miles range at least in a decent long downhill section, so you just need to trust your judgement and hold onto your bladder.

 

[Paul_Moxhay]

AFAIK it is a combination of things... the battery holds less charge the colder it is. That is the main factor. But other factors don't help... more heating, lights, rain, wind etc.

As for it improving as the battery warms... yes... I have not measured it but I noticed that it did on my London to Edinburgh trip in winter. Once the battery warmed up after a few rapid charges the range was noticeably better

 

[CoWplagued]

As stupid as it may sound cold air is also denser so you'd get greater drag at speed.
But for a long journey i'd expect a drop in range for the first leg as the car and battery warmed up, but then after the first rapid I doubt you'd notice much difference at all (in a mk2). I find Heating knocks about 1 mile off the motorway range as it's only on for an hour and you can keep it warm while charging.
One thing to bear in mind is that if it's really cold you need to allow extra time for that first rapid charge as it'll be a fair bit slower.

 

[Halldor]

I live in Norway and it gets cold here. These are the factors that mainly decrease range in the winter.
1. Cold equals less energy storage in the battery.
2. Winter tires that have more role resistance.
3. Cabin heater.
4. Wet or slushy roads plus wind.
5. Cold air is denser than warm air.

So what do I do when I go on long winter trips? Firstly I preheat the car having the temperature set to 30 Celsius. This I do when the car is unplugged. Why? Because this gets the juice flowing in the battery and warms it up slowly. OK so now I have around 76% battery. I drive to my local quick charger and charge to 90%. This warms the battery even more. Drive in eco mode and slowly but surely your battery will warm up and your range will increase. I also drive 10 km slower in the winter and this adds mileage.

I opted for Michelin X Ice i3 winter tires and I am hoping they give me a little more range than the Nokians Hakkapeliitta R2 did last winter?

With good preparation your Leaf will will not be a burden on long winter trips.

 

[donald]

Halldor has his list right. Not sure it is necessarily the right order but only because different things have a bigger or smaller impact at different times/situations.

Air is ~10% denser at 0C than at 25C. Because EVs take you right to the point of maximum efficiency, you begin to see more of the losses impacting your drive that are simply lost in the noise when compared with an ICE.

Wet roads also account for up to 10% losses. I did explain why this is so on leaftalk, but suffice to say someone summarised my long explanation, where I was desperately trying to avoid oversimplifying it, by saying 'wet roads are sticky' which seemed to get more resonance than my explanation! (sigh! )

I'm not overly convinced that colder batteries store so much less energy across the 0-20C range, but the BMS might well limit total energy available as a result of software measures to protect the battery. I think this might possibly be a bigger impact than a real physical reason.

Heating is a range killer. You can halve your range simply by trying to emulate an ICE. After all, they chuck out as much heat as they put into driving the car forward, so it is no surprise.

 

[gzoom]

I've noticed I'm now averaging 4 miles kWh compared to 4.5-5 miles per kWh. Same type of trips, same driving style. Not a huge issue, but 100%-20% range has gone from 75-80 miles to 50-60 miles.

 

[toscal353]

I've noticed I'm now averaging 4 miles kWh compared to 4.5-5 miles per kWh. Same type of trips, same driving style. Not a huge issue, but 100%-20% range has gone from 75-80 miles to 50-60 miles.

Yep! We have found the same.

 

[Scally]

Matter of interest, how do you get those figures? Is there some sort of quick trip summary menu you use?

 

[gzoom]

Matter of interest, how do you get those figures? Is there some sort of quick trip summary menu you use?

I simply reset the trip meter and efficiency screen every time I charge up. The efficiency display I find very useful, especially if your trying to work out how much range you have left given your current driving style.....When I need to rush and there is enough charge, the TC light on the dash board does make it self know on a few occasions

 

[Mr_G]

I've noticed I'm now averaging 4 miles kWh compared to 4.5-5 miles per kWh. Same type of trips, same driving style. Not a huge issue, but 100%-20% range has gone from 75-80 miles to 50-60 miles.

I have a different driving style but the same autumn drop from 5.5 miles/kWh to 5 miles/kWh. I have yet to do the first winter in the EV but the indications are that the loss is about 1% of best summer range per degree C fall and fairly linear. This is mainly due to the rising internal resistance of the battery as the battery mass gets colder. Increasing the current draw by inefficient electric cabin heating is a double blow because of the extra draw throu' the internal resistance (loss) and increased consumption (load). As the battery ages it is again rising internal resistance due to decay of the cells that reduces range capability.

 

[Sivart]

I have another Essex - Stoke trip planned in a few weeks.
In my Gen 2 at 65mph max, last time I looked to charge around 60 miles. What will this go down to now?

 

[Mr_G]

I have another Essex - Stoke trip planned in a few weeks.
In my Gen 2 at 65mph max, last time I looked to charge around 60 miles. What will this go down to now?

Only if it is really cold, the battery will warm with use and when rapid charging and partly offset ambient temperature so it is only the first leg that might have markedly reduced range. All depends on the temperature on the day.

 

[Paul_Moxhay]

I reduce my planned absolute max from 80 miles in summer down to 70 miles in winter.

 

[Sivart]

Only if it is really cold, the battery will warm with use and when rapid charging and partly offset ambient temperature so it is only the first leg that might have markedly reduced range. All depends on the temperature on the day.

Thanks, I plan on a quick top up charge at South Mimms and that is only 42 miles from home.
Toddington is another 30, so it's pushing it getting there in one hit.

 

[BarryP]

I have noticed that the tipping point for range for my LEAF is 10c air temp. Before a longish winter trio I tend to top up charge for an hour of so, plus use the preheat. The battery seems to warm slightly.
On a 450 mile trio last Feb the air dropped to 9c. and the battery only went to six bars even with repeat rapid charging.
The real killer for range is Rain, it takes extra energy to displace that water from the road surface as you effectively drive 'uphill' into the water.
On a virtually identical journey repeated over 20 months I found that Air temp had an effect, even if the battery was warm and no in car heating used.

 

[Mr_G]

Thanks, I plan on a quick top up charge at South Mimms and that is only 42 miles from home.
Toddington is another 30, so it's pushing it getting there in one hit.

Wise plan otherwise you would have no margin of error with a single leg of 72 miles (I would not attempt it) as a result of the lower range due to temperature, to say nothing of possible diversions. Quicker driving if the range holds up well will keep the battery warm and offset time for increased charging stops.

 

[Roarers]

Thanks, I plan on a quick top up charge at South Mimms and that is only 42 miles from home.
Toddington is another 30, so it's pushing it getting there in one hit.

South Mimms is very near me. Be prepared for queues at certain times of day/days of the week. Evening rush hour is and most weekends seem particularly busy, but you might just get lucky.

 

[Sivart]

South Mimms is very near me. Be prepared for queues at certain times of day/days of the week. Evening rush hour is and most weekends seem particularly busy, but you might just get lucky.

Yep, it was busy last time but only had to wait 10 minutes.