SOC-LCD-Meter "LeafCAN" with 2x16 Display by lincomatic

[lincomatic]

Having used the LeafCAN for the first time (and QC for the first time and second thru ninth time (!) ) while doing the Oregon BC2BC Return) ... (thanks, BTW !) ... I'd like to add my vote: keep it as is.

Counting Nissan's SOC bars while driving -- unless it's 11-12 or 1-3 -- is distracting; one look at the LeafCAN ... and it tells me digitally.

The SOC% and GID# and Amps completes the info I need. Although # of Temp bars might be good too (same problem counting them as GOM bars). (Actual temp would be better ... I know ... defer to Ingineer.)

Sorry, I didn't mean a graphic display. I agree with you about counting bars.. it's distractiing, which is why LeafCAN currently displays the fuel bars as a number. This new "fuel bars" display would also be digital, and would just replace the current display of GOM fuel bars.

 

[lincomatic]

I prefer knowing what I actually have to work with so I prefer 0 equal turtle level which I believe is 4 Gids...

Tony said that the only hardcoded value is dropping from 25->24 GIDs takes you into VLBW. How about if I make a new fuel bar display where <= 24 GIDs = 0, and from 25->281 GIDs is broken up into 12 equal increments from 1-12?

I thought about using turtle = 0, but by the time you get to turtle, you're already in big trouble. If you get to zero @ VLBW, it gives you some reserve to go find a place to charge. Between VLBW and turtle, you need a lot more resolution than the 12 steps would give you, so in this zone, you should really be using SOC values.

 

[GlennD]

I to prefer the bars taken from the buss.

I let my car sit several hours and then charged to 100%. I was back to 281. Charging a cold battery gives me 2 more units.

I usually charge to 80% when I park and that shows 82.5%

Since my power is not tiered I charge at once so I always have a charge available. The Leaf is my only car.

If we have power issues this summer I will then charge late at night.

 

[TomT]

OK, given that there is not much resolution to work with, I can appreciate that.

I thought about using turtle = 0, but by the time you get to turtle, you're already in big trouble. If you get to zero @ VLBW, it gives you some reserve to go find a place to charge. Between VLBW and turtle, you need a lot more resolution than the 12 steps would give you, so in this zone, you should really be using SOC values.

 

[lincomatic]

I to prefer the bars taken from the buss.

I let my car sit several hours and then charged to 100%. I was back to 281. Charging a cold battery gives me 2 more units.

I usually charge to 80% when I park and that shows 82.5%

Since my power is not tiered I charge at once so I always have a charge available. The Leaf is my only car.

If we have power issues this summer I will then charge late at night.

Your car is still young. The problem is, after your battery starts to wear, you'll start getting less consistent, lower values.
Mine has never shown 100% SOC, because the highest SOC I've ever gotten has been around 273. Last night's 100% charge was 259.
It's hard to estimate range for longer trips when 12 fuel bars can be displayed between 281 -> 259 GID's.

 

[surfingslovak]

Tony said that the only hardcoded value is dropping from 25->24 GIDs takes you into VLBW. How about if I make a new fuel bar display where <= 24 GIDs = 0, and from 25->281 GIDs is broken up into 12 equal increments from 1-12?

There are two hardcoded values: LB at 50->49 Gids or 4 kWh stored, and VLB at 25->24 Gids or 2 kWh stored. Both of these kWh values were quoted by Mark Perry at various occasions. Given Nissan's philosophy around the hidden reserve, I wouldn't expect those to change even as the battery degrades.

Although it depends on environmental conditions and driving style, I found LB to be an equivalent of 3.3 kWh usable, and VLB 1.4 kWh usable.

Assuming a balanced pack, power limited mode begins at 10->9 Gids, which is usually indicated by disappearing power rings on the dash, but this effect is not always observed. I have seen turtle kick in at 5 or 6 Gids.

Click to open

 

[LEAFer]

Having used the LeafCAN for the first time (and QC for the first time and second thru ninth time (!) ) while doing the Oregon BC2BC Return) ... (thanks, BTW !) ... I'd like to add my vote: keep it as is.

Counting Nissan's SOC bars while driving -- unless it's 11-12 or 1-3 -- is distracting; one look at the LeafCAN ... and it tells me digitally.

The SOC% and GID# and Amps completes the info I need. Although # of Temp bars might be good too (same problem counting them as GOM bars). (Actual temp would be better ... I know ... defer to Ingineer.)

Sorry, I didn't mean a graphic display. I agree with you about counting bars.. it's distractiing, which is why LeafCAN currently displays the fuel bars as a number. This new "fuel bars" display would also be digital, and would just replace the current display of GOM fuel bars.

No ... sorry from me now ... I think I emphasized the digital vs. graphical too much. What I meant was, don't change the digital # fuel bars from Nissan's count to a 1/12th of the SOC. The SOC is already given in % with 0.1% resolution; that's better than 1/12 = 8.33% resolution, so it does not really add anything. On top of that we have GID# to look at. The digital count of Nissan's GOM bars helps emphasize the GOM's (nebulous) relationship to SOC, and serves (for me at least) as an additional learning tool. (Yes I still have the graphical on the dashboard, but -- again -- that's too distracting to count while driving.)

 

[GlennD]

Oh, I know it is going to degrade. That is a fact of life for a Lithium battery. I would expect a 5% loss a year. The city that I work for changed over to Motorola XTS5000 portables in 2006. All of the 2007 date code batteries and most of the 2008 lithium batteries will not meet 80%

This is the primary reason that I leased. Let the problem be Nissan's.

 

[lincomatic]

I finally got my Reprap working well enough to start playing with case designs for LeafCAN. Here's my prototype, attached to a suction cup mount:

Wish LeafCAN were small enough to squeeze into the cowled area ... I think a perfect spot would be under the cowling, blocking the useless eco tree display.

More photos here: http://blog.lincomatic.com/?p=703

 

[lincomatic]

Tony said that the only hardcoded value is dropping from 25->24 GIDs takes you into VLBW. How about if I make a new fuel bar display where <= 24 GIDs = 0, and from 25->281 GIDs is broken up into 12 equal increments from 1-12?

There are two hardcoded values: LB at 50->49 Gids or 4 kWh stored, and VLB at 25->24 Gids or 2 kWh stored. Both of these kWh values were quoted by Mark Perry at various occasions. Given Nissan's philosophy around the hidden reserve, I wouldn't expect those to change even as the battery degrades.

Although it depends on environmental conditions and driving style, I found LB to be an equivalent of 3.3 kWh usable, and VLB 1.4 kWh usable.

Assuming a balanced pack, power limited mode begins at 10->9 Gids, which is usually indicated by disappearing power rings on the dash, but this effect is not always observed. I have seen turtle kick in at 5 or 6 Gids.

That's great info. Also good to know that the turtle may be looming before 4 GIDs.

Ingineer says that 80*GIDs = KWh, and I think TonyW likes 75. Your scale factor is even more conservative. How are you guys calculating "usable" KWh?
Right now, I'm just using Ingineer's number. For the purpose of the SOC meter, accuracy really doesn't matter; the only thing we really need is something that's consistent.

 

[lincomatic]

BTW, does anyone know where to get skinny OBD-II cables like the ones Ingineer uses for LeafScan? Mine is way too fat to squeeze into the crevice between the dash & the door.

 

[GlennD]

You can get a naked connector from sparkfun for $4.75. Since you only need power ground and 2 can wires the cable can be very small.

 

[surfingslovak]

That's great info. Also good to know that the turtle may be looming before 4 GIDs.

Ingineer says that 80*GIDs = KWh, and I think TonyW likes 75. Your scale factor is even more conservative. How are you guys calculating "usable" KWh?
Right now, I'm just using Ingineer's number. For the purpose of the SOC meter, accuracy really doesn't matter; the only thing we really need is something that's consistent.

Great point, thank you for raising it, Sam. I would use 21 kWh / 22.48 kWh = 74.73, which is 75 Wh rounded up. I believe that usable energy is tied to dash instruments, and although eminently practical and useful, it's not the most accurate or scientific approach. If you look at my usable energy estimates at LB and VLB, I'm very close to the ideal value. One could argue that more energy is lost in the battery at low SOC due to higher internal battery resistance, and as a result we get slightly less usable energy per Gid than the average of 75 Wh.

LB:

49 Gids - 4 Gids (reserve after turtle) = 45 Gids usable
45 Gids * 75 Wh/Gid = 3.4 kWh

VLB:

24 Gids - 4 Gids (reserve after turtle) = 20 Gids usable
20 Gids * 75 Wh/Gid = 1.5 kWh

 

[SierraQ]

Sounds like great work and I applaud you guys for advancing the knowledge of what goes on inside the Leaf!

The name sounds odd, though... I don't know if you and Ingineer consider each other competitors now but IMHO "LeafCAN" and "LEAFSCAN" sound just a little too similar. I think people will get these two efforts mixed up.

 

[Nekota]

Sounds like great work and I applaud you guys for advancing the knowledge of what goes on inside the Leaf!

The name sounds odd, though... I don't know if you and Ingineer consider each other competitors now but IMHO "LeafCAN" and "LEAFSCAN" sound just a little too similar. I think people will get these two efforts mixed up.

Good point and the first LEAFCAN was mentioned by Lincomatic in Feb, LEAFSCAN mentioned in March so they are close. Maybe LEAFCAN should add Gary's 'CanDo' to make it a LEAFCANDO to help distinguish the two.

 

[lincomatic]

Good point and the first LEAFCAN was mentioned by Lincomatic in Feb, LEAFSCAN mentioned in March so they are close. Maybe LEAFCAN should add Gary's 'CanDo' to make it a LEAFCANDO to help distinguish the two.

Yes, I posted about LeafCAN in my blog on Feb 18 http://blog.lincomatic.com/?p=459. It's unfortunate that LEAFSCAN has such a similar name. I didn't notice it until today. LeafCAN was an outgrowth of my Arduino CAN bus project, with Leaf-specific decoding of the CAN bus messages. Unlike LEAFSCAN, LeafCAN is and always will be an open-source project, with freely available source code for anyone to hack and modify to their heart's content. I don't consider Phil's commercial product to be a competitor, and I hope he doesn't feel that way about LeafCAN.

 

[garygid]

Many think of the "Fuel" bars on the dash as the amount of fuel,
much like an ICE would have, familiar and useful.

However, these Nissan-Bars are NOT "fuel", but "tank-fullness"
bars, of the (shrinking-size) "tank" (the Battery Pack).
When the Pack drops to 50%, and is charged "full" (to "100%"),
the LEAF will still show 12 "tank-fullness" bars.
Not directly useful for driving or estimating range.
And, misleading to most people familiar with ICE fuel gauges.

The GID value is more like a higher-resolution digital
fuel gauge, where we see lower "full" values as the
size of the LEAF's "tank" shrinks.

The %GID value tries to indicate the same "amount of fuel"
as an easier-to-use fraction of a full "new" battery Pack (tank).

For most people, visualizing the amount of fuel remaining is easier
as a percentage of a fixed reference value (the original tank size).

Seeing the digital "Bars" value is essentially as useless as
seeing the "bars" themselves.

Making a low resolution "fuel" value when when you already have
a higher-resolution value, serves no real useful purpose, IMO

 

[EdmondLeaf]

Good point and the first LEAFCAN was mentioned by Lincomatic in Feb, LEAFSCAN mentioned in March so they are close. Maybe LEAFCAN should add Gary's 'CanDo' to make it a LEAFCANDO to help distinguish the two.

Yes, I posted about LeafCAN in my blog on Feb 18 http://blog.lincomatic.com/?p=459. It's unfortunate that LEAFSCAN has such a similar name. I didn't notice it until today. LeafCAN was an outgrowth of my Arduino CAN bus project, with Leaf-specific decoding of the CAN bus messages. Unlike LEAFSCAN, LeafCAN is and always will be an open-source project, with freely available source code for anyone to hack and modify to their heart's content. I don't consider Phil's commercial product to be a competitor, and I hope he doesn't feel that way about LeafCAN.

I thank all of you very much for your work, we are very fortunate to use LeafCAN, it is such a great tool. As of adding battery temp it will be nice, but on other hand what is the use, if there is nothing we can do to control battery temp efficiently, beside parking in climate controlled garage.

 

[foobert]

Thank you all for the wealth of info here and elsewhere. I'm about to pull the trigger and order parts to build my own.

One thing I'm not getting a good handle on is what all information is available from each of the CAN busses? I've seen Gary's VarParmList.csv posted on his site, but, it is not entirely obvious what many of the fields are.

Is there a comprehensive list being maintained anywhere that verbosely describes all of the known canbus data variables/registers available?

Thanks!

~john

 

[Nekota]

Thank you all for the wealth of info here and elsewhere. I'm about to pull the trigger and order parts to build my own.

One thing I'm not getting a good handle on is what all information is available from each of the CAN busses? I've seen Gary's VarParmList.csv posted on his site, but, it is not entirely obvious what many of the fields are.

Is there a comprehensive list being maintained anywhere that verbosely describes all of the known canbus data variables/registers available?

Thanks!

~john

https://docs.google.com/spreadsheet/ccc?key=0An7gtcYL2Oy0dGRaSWl6VTV2eXBQMy1ON2xZSzlMUXc#gid=5" onclick="window.open(this.href);return false;