Shrinkage (Range That Is)

The forecast is for cold.  REALLY, REALLY cold.  Tomorrow morning's low is forecast to be 13°F with a high of 20°F.  But that's nothing.  Both this coming Saturday and Tuesday morning lows are forecast at 3°F!  That's cold for here even in January.  Saturday is no big deal because we won't be going anywhere, or at least anywhere far.  Tuesday I'll need to make it to the office and back.



That's leading to a return of a bit of range anxiety.  How much of the LEAF's range is going to be reduced by the cold weather?

From my reading there are two things that reduce a LEAF's range in cold weather, only one of which I have control over.  The first is use of the cabin heater.  A pair of my wool ski socks and lowering the ear flaps of my "Flying Nun" hat can help with that.

And Kerry talked about Guy’s daring headwear

The second is a reduction in battery capacity and performance.  The owner's manual states that range can be substantially reduced in extremely cold weather.  The example they give is -4°F.  That's the temperature at which the battery heater comes on to prevent the battery from freezing.  I'm thinking that 3°F is getting uncomfortably close to -4°F.  They also don't really define what "substantial" is.

I've read a few articles on how temperature effects range and at least one seems to show some numbers that make me feel a bit more comfortable.  If you take a good look at the graph in the article you'll see that at 32°F the range seems to be around 52 miles.  At that temperature, I've been getting a range closer to 100.  That gives me hope that at 3°F, where they're showing a range of around 42, I should be able to get at least somewhere in the 70s.

Plenty to get me to the office and back.  Especially since the high for Tuesday is forecast to be a balmy 27°F.

From what I'm reading cold affects the battery itself, beyond the use of the cabin heater, in the following ways:

• It's slower to charge.
• It reduces performance.  I'm guessing by slowing the rate at which it can discharge.
• It reduces the total capacity of the battery.
• Below a certain temperature (I'm guessing below-4°F) the battery will actually freeze and be unable to charge or discharge.

Note that I am absolutely no technical expert on batteries so the above may be slightly or wildly incorrect.
There are any number of articles such as this one on maximizing your range.  They pretty much say the same things as the owner's manual:

• Use the heated seats and steering wheel to reduce the need for cabin heating.  I'll add, wear a hat and wool socks.
• By doing the above, minimize the use of the cabin heater by setting it to a moderate temperature and not keeping it on the whole time you're driving.
• Preheat the car while it's plugged in.  I actually bump the cabin heater thermostat up few degrees for preheating to get that little extra bump in temperature and then lower it once I'm on the road.
• Park inside.  Even an uninsulated garage is usually warmer than outside and it's out of the cold wind.  Our garage is usually 5 to 10 degrees above the outside temperature in the winter.
• Keep the car plugged in when parked in extremely cold weather (< -4°F) so that should the battery heater engage it will use external power.
• Make sure your tires are up to the correct pressure as cold will cause a reduction in tire pressure leading to higher rolling resistance.
• An interesting idea I read in one of the comments of the above mentioned article is to schedule the car to complete charging when you're going to leave.  That way the battery is still warm from the charging process.  That may be why the owners manual suggests simply entering an end time when scheduling a charge rather than a start time.

We'll let you know how the LEAF performs over the next week or so of wintry weather.

Monday's Statistics

• Description: School and back
• Starting Range: 86 miles
• Miles Driven: 10.3 miles
• Ending Range: 75 miles
• High Temperature: 35
• Low Temperature: 24
• Wind: 7
• Average MPKWh: 4.0
• Average MPG: 24.5
• Energy Cost/KWh (Wind): $0.0899
• Delivery Cost/KWh: $0.092
• Unleaded Regular/Gallon MA: $3.448
• Savings/Mile: $0.095
• Total Savings: $0.98
• Lifetime Savings: $56.17
• EV Spotting: No

Yesterday's Statistics

• Description: Commuting,  a bit chilly
• Starting Range: 75 miles
• Miles Driven: 50.5 miles
• Ending Range: 28 miles
• High Temperature: 33
• Low Temperature: 24
• Wind: 13
• Average MPKWh: 4.0
• Average MPG: 24.5
• Energy Cost/KWh (Wind): $0.0899
• Delivery Cost/KWh: $0.092
• Unleaded Regular/Gallon MA: $3.452
• Savings/Mile: $0.095
• Total Savings: $4.82
• Lifetime Savings: $60.99
• EV Spotting: No

Yesterday's Additional Statistics

• Description: Lesson Taxi
• Starting Range: 41 miles
• Miles Driven: 18.6 miles
• Ending Range: 14 miles
• High Temperature: 33
• Low Temperature: 24
• Wind: 13
• Average MPKWh: 4.1
• Average MPG: 24.5
• Energy Cost/KWh (Wind): $0.0899
• Delivery Cost/KWh: $0.092
• Unleaded Regular/Gallon MA: $3.452
• Savings/Mile: $0.097
• Total Savings: $1.97
• Lifetime Savings: $62.79
• EV Spotting: No