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Re: LeafSpy..less than 100% at full charge?

Posted: Thu Jun 18, 2015 1:55 pm
by linkim
Turbo3 wrote:Keep in mind that SOC is not a direct indication of the energy in the battery. Just how full the battery is. As the battery ages it can hold less and less energy.

My 2011 when set to charge to 100% actually just charged to an SOC 91.71% but that is only 205 Gids or about 73% of the original capacity.

When new SOC was around 95% at full charge. So if you just looked at SOC change I have lost only 3.29% which is obviously not the case.

As a Leaf gets older SOC is of less and less value.

It does benefit Nissan as customers can not really see battery degradation in the SOC number now displayed on the dash. Someone buying a second hand Leaf would probably look at the SOC at full charge and think everything is still ok.
My analysis using WattsLeft and LeafSpy (both developed by turbo3) suggests the charge to 100% ends at 4.09xx V and 80% at 4.02xx V. As turbo3 mentioned, the SOC decreases as the Leaf gets older, but the average voltage at which 100% and 80% set points (MY11 Leaf) occurs is close to constant.

Re: LeafSpy..less than 100% at full charge?

Posted: Thu Jun 18, 2015 3:01 pm
by desiv
Turbo3 wrote:Keep in mind that SOC is not a direct indication of the energy in the battery. Just how full the battery is. As the battery ages it can hold less and less energy..
Makes sense..
So, does "Percent GIDs" work that way, or is that one constant over time?
i.e. if my battery degrades about 25% in 3 years, the max percent GIDs at a full charge would be somewhere around 75%, where as SOC could still be in the 95% range?

desiv

Re: LeafSpy..less than 100% at full charge?

Posted: Thu Jun 18, 2015 4:29 pm
by TimLee
TonyWilliams wrote:Turtle isn't based on GIDs. It's based on the lowest cell pair voltage reaching about 2.9 volts.

That can happen between 4-8 Gid typically. The app should use 6 Gid as a relatively predictable middle ground to show zero miles remaining.
I have been to Turtle three times in the past few months in a 2011 that has lost two capacity bars.
It is not based on GID.
All three times it has occurred when kWh remaining hits 0.4 kWh.
But the lowest cell voltage has varied.
It has sometimes been near 3.3.
Sometimes lower like 3.15.
But not as low as 2.9.

It appears to be based on kWh remaining.

And on one occasion the contactor opened at 0.3 kWh.
Often the car will shut down very quickly after Turtle.
You may be lucky to go a half mile.
And with the 20 kW motor power limit, on a steep grade lucky to climb at 10 to 15 mph.

Re: LeafSpy..less than 100% at full charge?

Posted: Thu Jun 18, 2015 4:31 pm
by TimLee
desiv wrote:...
So, does "Percent GIDs" work that way, or is that one constant over time?
i.e. if my battery degrades about 25% in 3 years, the max percent GIDs at a full charge would be somewhere around 75%, where as SOC could still be in the 95% range?

desiv
Correct.