Imiev measured data

Post by **offgridQLD** » Thu, 17 Jul 2014, 05:15

Why wouldn't it be correct?

13kwh ( output)for a new car it sure isn't going to be any more than that.

Based on our calculations my Imiev is only 12.44kwh. So it sounds reasonable that a brand new Imiev could be 13kwh (accessible) output capacity.

Try and think of a time you have consumed more than 13kwh from your battery (remember to take off regen whrs)

Yes I have taken more than that out ...

The lowest I have taken my battery is 13.5% on that trip I took 14.127kwh from the battery and reg 1.436kwh back so total out was 12.692kwh + 13.5% = 14.333kwh

So our measurements of 5% capacity x 20 for total 100% capacity must be wrong/not acurate as this gives me a capacity of 12.44kwh but as you can see on a trip not long ago I calculating from my consumed kwh and my % SOC I have 14.333kwh.

So We don't have numbers we can trust using canion or our SOC meter in the car. Nothing is consistent and they are not even close to one another . I cant trust the data.

Or perhaps you can trust the consumption data and reg data but the SOC% data you cant trust at all as it dosn't add up.

Kurt

Post by **g4qber** » Fri, 18 Jul 2014, 07:56

after turning off bluetooth audio on the nexus 7, connection has been stable so far.

one thing with the batman dongle is that one can switch between nexus 7 and ultra z, but with mx one has to unpair and pair.

will be interesting to see whether batman is less secure than mx.

xperia is running 4.4.2 android
nexus is on 4.4.3

Post by **offgridQLD** » Fri, 18 Jul 2014, 17:32

Today I repeated the charging test from 54% SOC on Canion to 59% SOC this 5% is one bar on the dash gauge. Always the same 5% this never chages like clockwork.

Last time 622whr 22min 44seconds

this time 622whr 22min 44seconds

So it's very repeatable.

The problem I still see is that if you take this 622whr - 5% and expand it out 20x to = 100% you come up with 12.44kwh and the laws of physics would show that you cant take out more than you have put in put in. (yes Regen was taken into account)

The issue I have with the 12.44kwh is I have taken out more than 12.44kwh shown in the very same meter that measures the 12.44kwh.

Kurt

Post by **me68** » Fri, 18 Jul 2014, 21:49

I also think 5%SoC charging/using is not suitable to calc whole battery capacity, because it's unknown to us, how SoC is calculated and if this is linear over the whole range.

Why not using f.e. 90%DOD or even more? I have done this twice with 98%DOD - see elweb.info Thread.

I get out first time 14.568Wh with 98%DoD ... is in total 14.865Wh useable battery capacity out and 14.700Wh with 98%DoD second time, which is in total 15.000Wh useable battery capacity out.

Martin

Post by **offgridQLD** » Fri, 18 Jul 2014, 22:18

Martin, did you remember to subtract the whr reg that was created in your log from the total 14.865Wh or was that after subtracting REG energy. Because the total canion gives includes energy consumed that was created by regen. For example 14.00kwh total out reg 1.00kwh = 13.00kwh from battery.

Edit: I see after reading your post you did take reg energy into account.

I don't want to assume anything and that's why its good to testing things to see if they can prove them self to be accurate/consistent or not. As soon as a measuring device or method proves it self not to be accurate or consistent I disregard any data from it as its pointless.

I will take the same 5% SOC test from 3-4 bars and then do the same test at 14-15 bars this should give some voltage spread and see what numbers I get. If they are different then it will show that you can not multiply 5% data x 20 for a 100% capacity. Though if it is actually counting capacity in whrs like it shows on the screen then voltage or SOC area that you take the reading from shouldn't matter and will be linear across the range.

Kurt

Post by **offgridQLD** » Fri, 18 Jul 2014, 22:35

the lowest data I have is at 13.5% SOC

14.127kwh out - 1.435 Reg = 12.692kwh + 13.5% = 14.405kwh

This was when I had 8000km on my car less then one year old.

Another one from the same month...

14.00% SOC

13.763kwh out - 1.385kwh Reg = 12.378 + 14% = 14.11092

As you can see one week 14.405kwh and the next 14.110kwh it's not constant and I'm am sure I can find some with wider spread from the same month.

The biggest discrepancy I can think of with how much capacity you can consume from your battery is how you discharge it. If you discharge your battery by driving up a mountain at 50kw consumption I am sure the total capacity available will be less than if you drove around in cycle in a car park at 20kph consuming 2kw. High discharge rates = less capacity.

To play a trick with canion Use the head lights of the car consuming just 100w with the ignition on and DC/DC converter as the only load Deplete your battery from 100% SOC over many - many days while logging to 0% SOC in cannon. I think you would be surprised that you can have a very large kwh capacity number perhaps 16.00kwh

Kurt

Post by **me68** » Sat, 19 Jul 2014, 01:30

offgridQLD wrote:I will take the same 5% SOC test from 3-4 bars and then do the same test at 14-15 bars this should give some voltage spread and see what numbers I get.

Hello Kurt!

The bars form the dashboard represent different Wh. So this is not an accurate method, also working with small ranges like 5% and interpolation to 100%.

Martin

Post by **Malm** » Sat, 19 Jul 2014, 01:43

Me68, OffgridQLD knows how much each bar represents and will measure exactly 5%.

So, OffgridQLD, now you see that i´m right. This is a good way to measure how different i-MiEVs behave. Mine will charge only 550 since march, because it recalculated its capacity at that time.

Post by **Malm** » Sat, 19 Jul 2014, 01:49

"I will take the same 5% SOC test from 3-4 bars and then do the same test at 14-15 bars this should give some voltage spread and see what numbers I get. If they are different then it will show that you can not multiply 5% data x 20 for a 100% capacity."

I have tested that, and kWh regen will be different in different ranges of 5%. And time needed will be different too.

It would be amazing to have this value for many i-MiEVs, I think most of them will do the same as yours.

Post by **offgridQLD** » Mon, 21 Jul 2014, 13:48

Fridays nights 105km trip data, (60kmh wind gusts and cold)

13,434kwh out 1.332kwh reg = 12.102kwh from battery SOC was 15.5% (though I started with 99.5%) So I will call it 16% SOC.

12.102 + 16% = (14.038kwh for 100%)

Recharging = 14.3kwh from wall + 16% = 16.558kwh

"I have tested that, and kWh regen will be different in different ranges of 5%. I think the time will be exactly the same, but because amperage is higher in the beginning of the charge, the kWh regen will be different too."

I would only test in a range that charges at the full 2200w Not the very end when it starts to decrease output.

Kurt

Post by **Malm** » Mon, 21 Jul 2014, 14:55

My last trip of 104,6 km

Wh Out - 12,368

Wh reg - 1,744

Wh in the battery - 10,624

Speed avg - 48,6 km/h

Soc - 100 to 20,5%

Voltage - 328

Altitude - going up 200/250 meters

Wh/km - 102

10,624 - 79,5% that is 100% - 13,36.

OffgridQLD trip 14,038 - Mine 13,36352 = Mine less 5% then the australian i-MiEV - I wasn't expecting to be so close.

Post by **Malm** » Mon, 21 Jul 2014, 15:28

My i-MiEV is now surprising me. Doing 5% less then an one year old is fabulous. After 3 years and 3 months, 70.000 km, It shows to have around 95% the energy of a 1 year old i-MiEV.

The last 9 months I think it recovery a little (very little) of capacity. That´s a big surprise too. Last September, the maximum kWh from the wall was 15,8. Now it can go to 16.

I'm doing everything that I can to keep the battery under 21 ºC. I made a bet with a Portuguese friend that owns a Leaf that I could do it, and at 12:00 I made it for more then one month, and now we are in summer time.

So, battery between 15-20ºC, 9 months, no degradation.

I´m more concerned now about the corrosion of the battery then of the degradation.

Malm, always with different ideas, always with new ideas, always with surprising facts. I hope you understand me. OffgridQLD is giving me a lot of support, a lot of hope, thank you.

Post by **offgridQLD** » Mon, 21 Jul 2014, 16:13

Well I purchased the car new - zero km on odometer (actually I think it had 4km) So yes sold as new car in 2013 just gone one year of ownership and 11,000km.

Though the car was build in Jan 2012 so battery's are 2 1/2 years old.

If you can still drive 100km distance Malm your car is still practical and doing well with 7x more mileage than mine.

Kurt

Post by **Malm** » Mon, 21 Jul 2014, 17:39

Maybe I still can repeat the 200 km with one charge I did last summer, at 40 km/h and with a difference in altitude of -500 m.

Post by **offgridQLD** » Mon, 21 Jul 2014, 19:34

on my 105km weekend trip. I have large hill + 550m altitude gain at 12% grade. I recover roughly 1kwh an the way home going back down. takes roughly 2kwh to climb up.

Kurt

Post by **Malm** » Tue, 22 Jul 2014, 01:16

In that weekend trip, you should not see any difference between what you spent of bars one year ago and now.

The difference will be on the voltage it gets to 0,0% SoC. Maybe one year ago it stopped with 310 total voltage, and now 300.

What is your best RR? I bet a little more then 155 km.

Post by **offgridQLD** » Tue, 22 Jul 2014, 01:24

No when I first got my imiev I could arive with 18.5 - 25% SOC usually 2 bars on the gauge. Now always one bar 13.5% - 18% though it could be winter temps giving less capacity. Summer will soon tell.

RR gauge is to easy tricked I take no notice of it . My typical avarage whr consumption is 100whr city 120whr country-freeway-hills.

Kurt

Post by **Malm** » Tue, 22 Jul 2014, 02:20

I should expect a little more then 5% difference between summer and winter.

Post by **offgridQLD** » Tue, 22 Jul 2014, 04:25

I think this is where we are see some error in canion.

http://www.myimiev.com/forum/viewtopic. ... &start=110

It looks like whrs out is accurate to the true value being taken from the battery but whrs reg doesn't take into account the inefficacy in getting that power into the battery. (just like charging from the AC wall there are inefficacy)

So for example 10kwh out with 2kwh reg wouldn't = 8kwh out from the battery. Perhaps only 1.5kwh of the Regen actually makes it back and is stored for reuse in the battery.

So in that example 8.5kwh out.

What needs to be determined is the efficacy from measured Regen whrs vs what the battery actually stores.

The only way to test this is to run the heater in the car perhaps Air conditioner at the same time to consume energy down to 20% SOC and see capacity (no Regen calculation needed)

Perhaps I will heat my workshop with my Imiev for this experiment

Post by **offgridQLD** » Fri, 25 Jul 2014, 17:14

Today I went over all my screen shots from one years logged trips on Canion. I put by hand all the data for all the recorded trips (same 103km trip each time around 40 trips in total) All down on one page to make it easy to do direct comparisons.

To sum up I have a worst trip and a best trip and then I picked one trip as my target trip ( a trip where I considered the target SOC at the end to be very near what I achieved and the conditions to be very average) I guess a trip to aspire to for me that's a trip when I reach my destination with around 20% SOC.

In March 14/2014 I made the 103.2km trip with 20.5% SOC (331v resting) with a average of 115whr/km. Total whr out was 13,252whr, total Reg 1,397whr (11% reg)

Last week July 18/2014 I made the same trip with with 15.5% SOC (327v resting) with a average of 117whr/km. Total whr out was 13,434whr, total Reg 1,332whr, (10% reg)

As you can see the numbers for total consumption and Reg are very similar though the SOC at the end is significantly different.I could put perhaps 0.5 0 - 1% down to the difference in readings but the 4-5% difference is there. The only difference in the two would be. Time (the battery's are 6 months older) and temperature its a lot colder in July(mean temp 12C) VS March (mean temp 21C)

Trip mid March

Same trip mid July

Kurt

Post by **me68** » Fri, 25 Jul 2014, 18:34

Interesting comparison!

Temperature is the magic word.

Martin

Post by **Malm** » Fri, 25 Jul 2014, 23:48

In a similar trip

The same 20,5% SoC - Malm: 12.368-1.744 = 10.624
OffgridQLD: 13.252-1.397 = 11.855

11.855/10.624 = 89,6%

ONE MORE TIME results show that my i-MiEV behaves like it has 10% less capacity that the one of OffgridQLD. Remember that we have similar climate, but mine has 2 years and 4 months more in the road and more then 70.000 km.

Post by **acmotor** » Sat, 26 Jul 2014, 02:57

It would be useful if you guys could record the kWh from the wall to recharge as well to complete the picture.

Post by **Malm** » Sat, 26 Jul 2014, 03:28

I usually get 15,8 kWh from 0 to 100. Sometimes 16 kWh.

Post by **offgridQLD** » Sat, 26 Jul 2014, 03:29

Acmotor,
I do record kwh from the wall plug but only when I am recharging back to 100% SOC.

I will start including it in there.

Tonight's trip. 1 whr less consumption than last week

that's constancy. 1% more regen than last week (dis it in B mode tonight)battery temp 0.1 difference. Pack Voltage identical. SOC 0.5% more (last week i started with 99.5% SOC) So identical.RR same.

So this same trip I do once every week I have become very consistent at driving it.

PS, Ac motor I will add recharge whrs once the car is full again.