arnis
Posts: 867
Joined: Sat Jan 23, 2016 3:21 pm
Delivery Date: 23 Jul 2014
Leaf Number: 015896
Location: Estonia, Europe

Re: 2018 Leaf battery overheating

Mon Jun 04, 2018 1:18 pm

40kWh Leaf has very basic battery overheat protection, similar to previous Leafs.
Throttled charging/regen and power output.
This also happened on 24kWh and 30kWh Leafs, but at much higher temperatures.
Something like 50-55C before charging current is reduced.
New battery supplier demanded more protection and Nissan had to agree.
And this is how RapidGate came to life.
New "logic" tries to avoid battery going over 30C to prolong life. Which is not possible at ambient 25*C or more.
And it gets very aggressive at 50*C. And this avoids going any higher.
AFAIK, even power output will be limited at very hot temps. That is mostly noticed by slower acceleration.
Max speed driving requires just 40-50kW power output so temp hardly changes top speed.

At least 40kWh Leaf will not degrade extremely fast if battery management throttles that much :lol:

Unfortunately Leaf2 doesn't have "keep battery cooler" button or "chill" button like Tesla has. But to do it manually:
Avoid heavy regen.
Avoid accelerations above 30kW.
void speeds above 100km/h 60mph.
Avoid charge state below 30%.
Short range EVs <30kWh -- Medium range: 30-60kWh -- Long range: >60kWh
Charging: Trickle <3kW -- Normal 3-22kW -- Fast 50-100kW -- Supercharging >100kW

SageBrush
Posts: 2395
Joined: Sun Mar 06, 2011 2:28 am
Delivery Date: 13 Feb 2017
Location: Colorado

Re: 2018 Leaf battery overheating

Mon Jun 04, 2018 3:14 pm

arnis wrote:Max speed driving requires just 40-50kW power output so temp hardly changes top speed.

Steady state speed on level ground ?
Much less kW, more in the range of 20 kW
2013 Model 'S' with QC & rear-view camera
Bought off-lease Jan 2017 from N. California
Car is now enjoying an easy life in Colorado
3/2018: 58 Ahr, 28k miles

arnis
Posts: 867
Joined: Sat Jan 23, 2016 3:21 pm
Delivery Date: 23 Jul 2014
Leaf Number: 015896
Location: Estonia, Europe

Re: 2018 Leaf battery overheating

Tue Jun 05, 2018 6:46 am

SageBrush wrote:
arnis wrote:Max speed driving requires just 40-50kW power output so temp hardly changes top speed.

Steady state speed on level ground ?
Much less kW, more in the range of 20 kW


Not kW per distance but kW per time. Battery doesn't care about vehicle speed.
It cares how fast is energy flowing. Looking at power gauge it stays between 40-45kW at full speed 145km/h.
Short range EVs <30kWh -- Medium range: 30-60kWh -- Long range: >60kWh
Charging: Trickle <3kW -- Normal 3-22kW -- Fast 50-100kW -- Supercharging >100kW

SageBrush
Posts: 2395
Joined: Sun Mar 06, 2011 2:28 am
Delivery Date: 13 Feb 2017
Location: Colorado

Re: 2018 Leaf battery overheating

Tue Jun 05, 2018 8:31 am

arnis wrote:
SageBrush wrote:
arnis wrote:Max speed driving requires just 40-50kW power output so temp hardly changes top speed.

Steady state speed on level ground ?
Much less kW, more in the range of 20 kW


Not kW per distance but kW per time. Battery doesn't care about vehicle speed.
It cares how fast is energy flowing. Looking at power gauge it stays between 40-45kW at full speed 145km/h.

I have no idea what kW per time or kW per distance means in this context. kW per distance is nonsensical and kW per time is the rate of change of power.

I admit though, I was thinking more in the 70 - 75 mph (110 - 120 kph) speed range.
According to my aero drag and tyre friction table, 140 kph in a LEAF at sea level is 31 kW. Add in drivetrain losses and assorted fixed loads and I would guess ~ 35 kW steady state speed on level ground.
2013 Model 'S' with QC & rear-view camera
Bought off-lease Jan 2017 from N. California
Car is now enjoying an easy life in Colorado
3/2018: 58 Ahr, 28k miles

arnis
Posts: 867
Joined: Sat Jan 23, 2016 3:21 pm
Delivery Date: 23 Jul 2014
Leaf Number: 015896
Location: Estonia, Europe

Re: 2018 Leaf battery overheating

Tue Jun 05, 2018 11:05 am

kW per distance is kWh/100km or Wh/km (this unit is used for "fuel consumption" in many places).
Unit per time is regular kW. Regular power output.
Check this example (bad weather, slightly better in ideal conditions).
https://youtu.be/HIwQ09CajIY?t=2m10s
At max speed, more than half of bubbles (more than half of motor power, half of 80kW) are in use.
Even though it shows 160km/h 99mph, it's actually less. Speedo error (legal s**t).
Short range EVs <30kWh -- Medium range: 30-60kWh -- Long range: >60kWh
Charging: Trickle <3kW -- Normal 3-22kW -- Fast 50-100kW -- Supercharging >100kW

SageBrush
Posts: 2395
Joined: Sun Mar 06, 2011 2:28 am
Delivery Date: 13 Feb 2017
Location: Colorado

Re: 2018 Leaf battery overheating

Tue Jun 05, 2018 3:44 pm

arnis wrote:kW per distance is kWh/100km

It is not
Learn the difference between power and energy.
2013 Model 'S' with QC & rear-view camera
Bought off-lease Jan 2017 from N. California
Car is now enjoying an easy life in Colorado
3/2018: 58 Ahr, 28k miles

arnis
Posts: 867
Joined: Sat Jan 23, 2016 3:21 pm
Delivery Date: 23 Jul 2014
Leaf Number: 015896
Location: Estonia, Europe

Re: 2018 Leaf battery overheating

Wed Jun 06, 2018 7:33 am

SageBrush wrote:
arnis wrote:kW per distance is kWh/100km

It is not
Learn the difference between power and energy.


Extremely unuseful post :roll:
Short range EVs <30kWh -- Medium range: 30-60kWh -- Long range: >60kWh
Charging: Trickle <3kW -- Normal 3-22kW -- Fast 50-100kW -- Supercharging >100kW

User avatar
Nubo
Posts: 4771
Joined: Fri May 28, 2010 11:01 am
Delivery Date: 31 Oct 2014
Location: Vallejo, CA

Re: 2018 Leaf battery overheating

Wed Jun 06, 2018 10:45 am

arnis wrote:kW per distance is kWh/100km or Wh/km (this unit is used for "fuel consumption" in many places).
Unit per time is regular kW. Regular power output. ...


Nope, because of the "h". Watt-hour is a measure of energy. Watt is a measure of power or force; it's an instantaneous measurement. It exists outside of time or distance. In order for those Watts to perform work, they must be sustained over a given amount of time.

One thousand Watts sustained for an hour is one kWH.
Five thousand Watts sustained for 12 minutes is also one kWH.
One thousand Watts sustained for ZERO time, is simply one kW. No work has been performed, it's merely a potential.

"kiloWatts per kilometer" makes no sense; kiloWatt-hours per kilometer does.
I noticed you're still working with polymers.

arnis
Posts: 867
Joined: Sat Jan 23, 2016 3:21 pm
Delivery Date: 23 Jul 2014
Leaf Number: 015896
Location: Estonia, Europe

Re: 2018 Leaf battery overheating

Wed Jun 06, 2018 11:14 am

Ye I know ;)
Short range EVs <30kWh -- Medium range: 30-60kWh -- Long range: >60kWh
Charging: Trickle <3kW -- Normal 3-22kW -- Fast 50-100kW -- Supercharging >100kW

Return to “Batteries & Charging”