What's a Gid?

[pyrotech]

Sorry. I'm new at this. I've tried searching, but no joy.
What is a Gid?
Thanks in advance.

 

[Wennfred]

Posted by abasile · 1 year ago

A "gid" meter reports state of charge in terms of the amount of energy the LEAF estimates it has stored, as read from the CAN bus that's normally used for diagnostic purposes. The smallest reported unit of stored energy is approximately 80 watt hours and is nicknamed the "gid" in honor of Gary Giddings, the inventor of the small device that reads this data.

I use a device called LeafDD and it shows you the GID's and other readings, if you have an Android device as in a Tablet or phone you can download and install Leaf Spy or Leaf Spy Pro to view these figures.




Fred

 

[cwerdna]

http://www.mynissanleaf.com/wiki/index.php?title=Glossary" onclick="window.open(this.href);return false;

 

[ObiQuiet]

It would be good if the wiki explained how linear or non-linear the correlation between Gids values and the SOC% reported by the dashboard are to each other.

 

[cwerdna]

It would be good if the wiki explained how linear or non-linear the correlation between Gids values and the SOC% reported by the dashboard are to each other.

Would be nice, except that the gids were discovered WAY before the 2013 Leafs became available. '11 and '12 Leafs have no % SoC display. They've only got the GOM, the 12 "fuel bars" and the estimated time to charge.

 

[Staque]

It would be good if the wiki explained how linear or non-linear the correlation between Gids values and the SOC% reported by the dashboard are to each other.

Would be nice, except that the gids were discovered WAY before the 2013 Leafs became available. '11 and '12 Leafs have no % SoC display. They've only got the GOM, the 12 "fuel bars" and the estimated time to charge.

I've been using Leaf Spy on my 2013 for about five months, and the dashboard SOC is always the same as Leaf Spy's % GIDs, except when the dashboard says 99% or 100%. The SOC % in Leaf Spy is usually different by 1% to 4%. So I'd say the dashboard SOC is quite good, except at low SOC when it disappears.

 

[TomT]

The problem with SOC is that it does not represent a constant amount of energy... As the battery degrades, each SOC percentage will represent a smaller and smaller amount of energy... With Gids, the amount of energy represented remains basically constant. Think of it this way: SOC represents the amount of energy in the tank, regardless of the size and capacity of the tank. GIDs represents the amount of energy in the tank regardless of the size and capacity of the tank...

I've been using Leaf Spy on my 2013 for about five months, and the dashboard SOC is always the same as Leaf Spy's % GIDs, except when the dashboard says 99% or 100%. The SOC % in Leaf Spy is usually different by 1% to 4%. So I'd say the dashboard SOC is quite good, except at low SOC when it disappears.

 

[Boourns]

The problem with SOC is that it does not represent a constant amount of energy... As the battery degrades, each SOC percentage will represent a smaller and smaller amount of energy... With Gids, the amount of energy represented remains basically constant. Think of it this way: SOC represents the amount of energy in the tank, regardless of the size and capacity of the tank. GIDs represents the amount of energy in the tank regardless of the size and capacity of the tank...

Excellent point. If you have a Mini and a Suburban, both with an 80% full gas tank, you would have two very different absolute gallons of gas, versus having 12 gallons in both tanks.

 

[pyrotech]

Thanks, the Glossary was particularly helpful.

 

[ObiQuiet]

As the battery degrades, each SOC percentage will represent a smaller and smaller amount of energy... With Gids, the amount of energy represented remains basically constant.

Very clear, thank you!

 

[Staque]

The problem with SOC is that it does not represent a constant amount of energy... As the battery degrades, each SOC percentage will represent a smaller and smaller amount of energy... With Gids, the amount of energy represented remains basically constant. Think of it this way: SOC represents the amount of energy in the tank, regardless of the size and capacity of the tank. GIDs represents the amount of energy in the tank regardless of the size and capacity of the tank...

The question was whether the dashboard SOC is linear with respect to GIDs. The answer is, in my experience, yes.

 

[Gearscout]

I'm trying real hard...but when I read:

Think of it this way:

SOC represents the amount of energy in the tank, regardless of the size and capacity of the tank.

GIDs represents the amount of energy in the tank regardless of the size and capacity of the tank...

That doesn't quite make crystal clear the difference between the two. Or did I miss this completely? Are the two supposed to be identical?

I thought GIDs represented the absolute capacity of the tank.

From the Wiki:

GID: Unit of Charge reported by Gary Giddings' SOC meter. 1 Gid = 80Wh nominally, 100% Charge = 281 Gids on a new battery in a cold climate. "HV Battery Level" in Nissan vernacular. CAN bus message 0x05BC and displayed in Wh.

So, I may have a 2 year old battery that shows 100% SOC but only has 220 Gids...meaning it won't nearly go as far as a new battery that is also fully charged.

 

[TomT]

I'm trying real hard...but when I read:

It SHOULD say:

SOC represents the percentage of energy in the battery, from full to empty, regardless of the absolute capacity of the battery.

GIDs represents the absolute amount of energy in the battery and that amount will decrease as the battery degrades and with changes in temperature.

 

[TomT]

It may or may not be linear but the amount of energy represented by each percent point will both change with temperature and decrease as the battery degrades...

The problem with SOC is that it does not represent a constant amount of energy... As the battery degrades, each SOC percentage will represent a smaller and smaller amount of energy... With Gids, the amount of energy represented remains basically constant. Think of it this way: SOC represents the amount of energy in the tank, regardless of the size and capacity of the tank. GIDs represents the amount of energy in the tank regardless of the size and capacity of the tank...

The question was whether the dashboard SOC is linear with respect to GIDs. The answer is, in my experience, yes.

 

[michapok]

On my 2013 SV the GIDs are linear until they get down to something like 25 or so, at which point they stop changing for about 5% of SOC or so, then they start counting down again.

The relationship between dashboard SOC and LeafSpy SOC is likewise linear down to a certain point (around 50% or so) then the dashboard percentage start dropping faster than LeafSpy's until it's about 9% lower. It will stay that way until the dash gets down to ~5% after which point I get --- on the display.

Unfortunately I've only done the 'drive till nearly empty' trip twice so I don't have more data, particularly on the GIDs pausing their countdown. The 'reserve' SOC as I call it happens whenever I go below that 50% or so. I know others have charted this in another post. FWIW the LeafSpy SOC is the only measure that seems to stay linear throughout the drive.