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Re: *NEW* Dash Display for Leaf

Posted: Tue May 14, 2013 12:51 pm
by TomT
Under the dash to the left of the steering column and to the right of the hood and charge port levers.
thankyouOB wrote:where is the OBD2 port? i see some images online but they appear to be all japanese versions with righthand drive.

Re: *NEW* Dash Display for Leaf

Posted: Tue May 14, 2013 2:12 pm
by dgpcolorado
I'm puzzled by what you mean by "precise SOC" and how it differs from GID% or Ah%. [I just assumed that the %SOC display on the 2013 LEAF is a GID%, is that not the case?]

Regardless, any of the usual measures discussed plus your current in/out display and battery temperatures would be of great interest to me. I am especially curious to see how the temperature changes as I climb and descend hills, a routine part of my driving. (The utility of the voltage display I don't really understand, need to think about that some more...)

I like it!

Re: *NEW* Dash Display for Leaf

Posted: Tue May 14, 2013 2:45 pm
by TomT
No, it is percent of the available battery capacity so as the battery degrades, the amount of power per percent will drop. It is not a constant such as SOC based on Gids which is an absolute percentage... Think of it as a percentage meter based on the battery charge bars...
dgpcolorado wrote:[I just assumed that the %SOC display on the 2013 LEAF is a GID%, is that not the case?]

Re: *NEW* Dash Display for Leaf

Posted: Tue May 14, 2013 4:07 pm
by GregH
dgpcolorado wrote:I'm puzzled by what you mean by "precise SOC" and how it differs from GID% or Ah%. [I just assumed that the %SOC display on the 2013 LEAF is a GID%, is that not the case?]

Regardless, any of the usual measures discussed plus your current in/out display and battery temperatures would be of great interest to me. I am especially curious to see how the temperature changes as I climb and descend hills, a routine part of my driving. (The utility of the voltage display I don't really understand, need to think about that some more...)

I like it!
Thanks! Having the temperature info has sure been enlightening to me in the last few weeks.. For example, parking in the sun for a few hours isn't as bad as parking on hot pavement.. The car absorbs more heat from the ground beneath it than the hot cabin above it..

I haven't played with the SOC on the new 2013s but I have seen photos of 100% at "full".. I presume it's 0% when the car stops? Or at low power turtle mode?

It turns out that active polling of the CAN bus (ie asking for info rather than just listening to the other controllers talk to each other) can get a precise (XX.XXXX%) SOC reading just like the passive 0x55b message discovered a while back but with much more precision (3 more decimal places worth!.. although I'm only displaying 2 decimal places, the less significant digits move too rapidly to be useful.. You can still see the full precision on page 2 of the display if you wish).
So the raw precision SOC will be a number that (regardless of your car's battery capacity) will charge up to about 94.50% to 96.20% (in most cases). Incidentally you will find days with higher GID counts that also had the car charging to a higher SOC... ie some days 272 Gids @ 94.6% and some days at 274 Gids at 95.4% (for a reasonably healthy car with about 64Ah capacity..)

As others have pointed out the only true marker for LBW and VLBW is Gids.. When you go from 50 to 49 that's Low Battery.. When you go from 25 to 24 that's Very Low Battery. As for turtle and absolute dead stop that's harder to say.. usually around 4-8Gids. It probably has more to do with absolute cell voltages than anything. Page 3 on the LeafDD shows all the cell voltages as well as minimums and maximums..

Gid% (Gid*.356) is just provided for those who prefer to see Gids converted to a percentage but note due to space constraints on the screen the LeafDD can't display more than 99.99% So any new cars with 282Gids still get 99.99%. I'm merely providing this option for people with older vehicles who have grown accustomed to seeing Gids this way.

I think the 4th option, Ah% or Ah capacity * precision SOC will be most interesting. It's very much like Gids in that the units are constant with respect to the capacity of your car but with more precision and less hysteresis so you can see the regen you're getting going down a hill..
A new 2012 Leaf has about a 66Ah capacity and will charge up to 278-281Gids.. Such a car would show something like 62.96 when full (66.00*95.40).
A sun baked Phoenix car might have a 52Ah capacity (maybe 220Gids full?) but still charge to the same 95%.. so on wake up they might see about 49.40.

I was hesitant to add yet another energy number to the mix but it's really just two existing numbers in the raw data multiplied together (Capacity * SOC) with no additional constants added. I'd recommend people unfamiliar with this stuff just start off with the raw Gids (easy to digest) or the precision SOC which is fun to watch but keep in mind that unlike Gids, the units will change with the capacity of your pack.. The 66Ah new car and 52Ah sun baked car will both charge up to about 95% but the latter will have proportionally fewer Gids (and Ahs).

Re: *NEW* Dash Display for Leaf

Posted: Tue May 14, 2013 8:15 pm
by dcpatters
I'd like to be on the list for one. What do you need from those interested?

Re: *NEW* Dash Display for Leaf

Posted: Tue May 14, 2013 10:57 pm
by garygid
No need to show %GIDs with more than one decimal place.

Re: *NEW* Dash Display for Leaf

Posted: Tue May 14, 2013 11:29 pm
by GregH
garygid wrote:No need to show %GIDs with more than one decimal place.
True, but it's using the same display infrastructure as SOC and Ah.

Re: *NEW* Dash Display for Leaf

Posted: Wed May 15, 2013 11:01 am
by dgpcolorado
GregH, That explanation of the various measurements and their respective limitations helps a lot. Thanks.

From my perspective, the advantage of a fixed measurement unit, whether GIDs or Ah, is that one can learn what it takes to make a particular trip under various conditions. In another Winter or two I am going to have difficulty making my long trips in very cold weather. If I know how much energy I need to get home I can make the decision whether or not to find an outlet and charge a bit, and how much, to make it the rest of the way. So, some sort of absolute measurement is more useful than a relative percent of the degraded battery pack, no surprise!

Measuring mileage efficiency and trying to extrapolate that to remaining distance, as so many do, isn't useful where I live because my mountainous terrain is much too complex for such simple averages. Hence, the need for some sort of fixed energy unit. If it takes 3.5 Ah to make it home at 20ºF and I have 4.1 left, then I am good to go. If I only have 2.9 Ah then I need to stop at an outlet and plug-in.

Re: *NEW* Dash Display for Leaf

Posted: Mon May 20, 2013 8:11 am
by TaylorSFGuy
dcpatters wrote:I'd like to be on the list for one. What do you need from those interested?
I too would like to get on a list for one. Do you have pictures of the fully assembled unit?

Re: *NEW* Dash Display for Leaf

Posted: Mon May 20, 2013 10:30 am
by GregH
TaylorSFGuy wrote:
dcpatters wrote:I'd like to be on the list for one. What do you need from those interested?
I too would like to get on a list for one. Do you have pictures of the fully assembled unit?
Not yet.. Here's the CAD drawing for the enclosure:
Image
I'm having a few done at Shapeways but for production will be working with a local company here in Southern California.
I'll have 15 units up and running by the end of this week but no enclosures for probably another 2 weeks. :(
I'm still making a few final tweaks to the software and would like to try it out on a 2013 Leaf..
Would there be any SoCal folks interested in banging on one (figuratively) next week (for a week)?
They wouldn't have enclosures, but just to check things out before selling to the public.
I'm also curious to hear where people would like to mount it. It's pretty small and light but has that standard OBD2CABLES.com 6ft right angle connector cable on it.