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Earlier this week with ambient temperature 10 to 12 degrees I was getting a range of around 32 miles, Today with ambient 12 to 15 degrees I got 39.5 miles. All vehicle settings were identical and driving style not intentionally different. I noticed a similar step in range at these temperatures last year. It would appear that a heavy power consumer is switched off at around 13degrees. I suspect it might be related to battery temperature management. Anyone have any thoughts or knowledge?
 

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Funnily enough thinking exactyly the same this morning when my range also increased. Same last spring, there is definitely a step function involved, and agree with you that its most likely the battery temperature regulation.
 

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I did a "regular" journey to visit my Son yesterday and retured with 9 miles of range left, whereas last week doing the exact same Trip/route caused the range extender to have to kick in 2 miles from home. I seem to recall it was exactly the same last year when Spring arrived!

Just need the golf course to dry out and all will be well again.

Big Paul
 

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Has anyone come up with any better explanation, (since March 2014), as to what are the actual causes of the relationship between range and temperature?
 

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All vehicle settings were identical and driving style not intentionally different.

Just not possible.
Hot and low pressure air gives lower density gives lower drag
Hot road surface will increase tyre pressures
Difference in wind strength and direction. Noting that going upwind is not balanced by going downwind.

and then there is battery chemistry.
 

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It's down to battery chemistry and temperture, it all depnds on how much the battery heater runs or not and the transition temperature for the heater is around 12 degrees. the heater is 1.8Kw so its very thirsty on juice.
 

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That's interesting about 12 deg. The range is much better once you get to about 12 - 13 deg, like 15 miles further.
Anyone any idea of the optimum temperature for best range?
 

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It seems warm batteries accept the regen current better too. Mid 20's seems a sweet spot, thin air, better discharge capacity, better charging. any hotter and there is a point the AC comes in to cool the batteries.
 
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What temperature was it when you got this? Very jealous, I'm getting 42 at the moment
It was around 15c this morning I guess. I've only had the car 2 weeks, first charge was 33 & it has just got better & better. Just checked now, 48 with 40mins to run. I managed a 54 mile pure electric run to Oxford on Friday. I am loving this car!
 

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The car has been baking most of the day, not the best parking space :( So set off, all windows open and a gentle waft through town driving the heat out, Fans on to cool the ducts as much as anything. Down to the motorway, Fans on but no aircon, not bad now, down a long drag and cold air comes out of the vents - It seems the discharge and regen has heated the battery enough to turn on the AirCon to cool the battery :eek: Climate shows AirCon OFF. Once off the motorway and stopped at a roundabout the idle is 1 to 1.5kw not the usual 0.5 kw

This is the first time I've had the AirCon start itself whilst driving. BCDTT might be a suitable acronym (Battery Cooling Due To Temperature) compare to ERDTT, Engin Running Due To Temperature. :ROFLMAO:

Told you, the Ampera cares more for its battery than its occupants :D:ROFLMAO::ROFLMAO:
 
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Perhaps the green energy ball should be more like this...



Cheers,
Jim

Parked in the heat I ran the preconditioning for 10 minutes to cool the cabin.

The AC could be heard blasting away, and after a few minutes I jumped in to enjoy the coolness.

However the cabin was still red hot with no cool air blowing.

It would appear the car had turned off life support and was busy cooling its battery.

Definitely a HAL9000 processor at work here.
 
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