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Spy Vs Spy: Who has the correct SoC ?

Posted: Mon Aug 14, 2017 12:14 pm
by SageBrush
Hi all,

I've been charging up my car to 80 or 100% followed by a long drive to hit a low SoC in an attempt to recalibrate the LeafSpy's battery capacity readings. I've noticed that the SoC reading at the end of my drive has been at least 5% greater in the LeafSpy than the reading in the car display.

Is this just a case of different start and/or end points, a calibration problem, or an error ? I want to know because I am tying to figure out maximum usable kWh capacity by calculating the kWh used on a trip normalized to a 100% SoC use

Addendum:
I've run this long drive twice now.
Drive #1, the SoC delta was 9% (19% on the LeafSpy, 10% on the LEAF)
Drive #2, the SoC delta is 8% (21.9% on the LeafSpy, 14% on the LEAF)

More drives will tell if I have a trend, or perhaps even a return to same values.

In the meantime, can someone please explain how the SoC is derived in both the LEAF and LeafSpy ?

Re: Spy Vs Spy: Who has the correct SoC ?

Posted: Mon Aug 14, 2017 12:38 pm
by GerryAZ
The dashboard display shows full charge as 100% and starts with 0% at shutdown (fully discharged) while Leaf Spy reads "true" SOC from the Lithium Battery Controller so it has 97% or so as maximum at full charge and a few percent at shutdown since the LBC reserves some capacity at top and bottom to protect the battery.

Re: Spy Vs Spy: Who has the correct SoC ?

Posted: Mon Aug 14, 2017 12:58 pm
by SageBrush
GerryAZ wrote:The dashboard display shows full charge as 100% and starts with 0% at shutdown (fully discharged) while Leaf Spy reads "true" SOC from the Lithium Battery Controller so it has 97% or so as maximum at full charge and a few percent at shutdown since the LBC reserves some capacity at top and bottom to protect the battery.

Thanks Gerry.

So that could explain up to 2% at the lower SoC values. Any ideas about the remainder ?