Author Topic: Nissan Leaf battery.  (Read 1325 times)

Offline DavidA

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Nissan Leaf battery.
« on: August 17, 2018, 06:29:25 PM »
I was looking at an article on the Battery life of the Nissan Leaf, and the following opening remark struck me as a bit odd.


A Study on Real-Life Nissan Leaf Battery Deterioration
by Erin Yurday

The new 40 kWh Nissan Leaf has a real-life range of 170 miles (160 miles in summer and 180 miles in winter). But how does this range change over your first few years of car ownership?

How can the car have a greater range in winter, when I assume the lights, heater etc are used more, than in the summer ?

I wasn't sure where to post this snippet, any mod feel free to move it to somewhere more appropriate.

Here is the link if you want to read more.

https://www.nimblefins.co.uk/nissan-leaf-battery-capacity-range



Dave.

Offline russ57

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Re: Nissan Leaf battery.
« Reply #1 on: August 17, 2018, 08:33:27 PM »
I would think aircon use would explain that. Heating can use some recovery from the motor.

My outlander phev shows an instant electric range drop of 10% when the a/c is turned on.

Obviously dependant on climate...

Russ


Offline PekkaNF

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Re: Nissan Leaf battery.
« Reply #2 on: August 18, 2018, 03:24:03 AM »
I know that battery charge/discharge is very dependent on battery temperature. I don't know that battery chemistry, each has it's own quirks and often they are not intuitive.


I know that lead-accid batteries can be optimized for cold and low altitude or higher ambient temperature, but not both. I know that because sometimes our winters are that cold that battery is having a hard time cranking the engine and then it does not charge in first 10 Km, because battery is too cold. I need an external charger that charges the battery and warms up the engine when it is close to -30C, which does not happen often but there is one to three week cold period. This is where it gets weird: the startting battery does not give easily cranking current or take charge when it is cold, on the other hand it does not seem to loose charge that fast either. The external charger has temperature control and is located close to battery, it charges with somewhat higer voltage on winter than on summer.

Pretty sure that OP observation is least partly caused by battery temperature induced.

Pekka

Offline patuca

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Re: Nissan Leaf battery.
« Reply #3 on: October 24, 2018, 12:16:04 AM »
The resistance of metals increases with temperature, for example the Temperature Coefficient of Copper (near room temperature) is +0.393 percent per degree C. This means if the temperature increases 1C, the resistance will increase 0.393%.

The Nissan Leaf battery pack has huge current and grounding straps internally in the pack and externally (silver-coated copper is the usual conductor).  The battery pack has a possible output of more than 180A at 384V, or 70+ kW so even a small change in ambient temperature would make a difference in the internal resistance of the battery (and connections)  and change the system efficiency.

I couldn't resist a guess,

I edited the first line....of course I shoulda said "the resistance"  of metals increases with temperature.

patuca
« Last Edit: October 24, 2018, 06:25:19 PM by patuca »