bobakka
Posts: 36
Joined: Mon Nov 03, 2014 8:03 am
Location: Oslo, Norway

Re: Canion Battery Readings

Sun Dec 14, 2014 6:35 am

jray3 wrote:
bobakka wrote:I have owned my imiev for almost 4 years and been driving 77777 km. My 80% capacity guarantee expires in 14 months or 22222 km. I am positive that I have a range decrease, but it is very difficult to calculate how much. So how do I open a guarantee case against Mitsubishi if I need to?

What 80% capacity guarantee? Is that unique to the Norwegian market, and where else? IIRC, the US-market cars have no capacity guarantee.

Mitsubishi gave us a 80% capacity guarantee for 5 years / 100000 km in the Norwegian market. It is also documented in elbil.no. But I have never heard ony any that has been claiming that guarantee. I problems is maybe how you measure the capacity reductions. Probably it is by using amp hours.
iMiev; New Feb 2011; 119000 km January 2017

RobertC
Posts: 292
Joined: Fri Jul 27, 2012 7:35 am
Location: Winter Garden, FL

Re: Canion Battery Readings

Sun Dec 14, 2014 7:18 am

jray3 wrote:Btw, I got the dealer to run a battery capacity test during the rusty bolt recall work, and it came back at 42.6 Ah.
From the service manual, checking the battery capacity is a quick procedure using the MUT-III scan tool.

Image

I wish that battery capacity was part of Canion, then Mitsubishi i EV owners could compare battery capacity all around the world.

What an awesome database that would be!
”Red” - 2018 Red Dual Motor All-Wheel Drive Tesla Model 3 - 11/27/18
“Blue” - 2018 Kinetic Blue Chevy Bolt Premier with QC - 5/13/18
"Purple" - 2012 Raspberry Metallic ES with QC - 4/10/2013

siai47
Posts: 363
Joined: Fri Jun 14, 2013 5:54 pm

Re: Canion Battery Readings

Sun Dec 14, 2014 7:31 am

I've looked at that line in the diagnostics before and think it would be an indication of capacity but not true capacity. I think that what you would be looking at would be the BMU's calculation of the capacity based on time since new, cycles and miles driven---not actual capacity. The actual capacity test involves a complete discharge of the pack while connected to the M.U.T. III and takes several hours to complete. I don't know if a successful full test resets the BMU's calculation or not.

RobertC
Posts: 292
Joined: Fri Jul 27, 2012 7:35 am
Location: Winter Garden, FL

Re: Canion Battery Readings

Sun Dec 14, 2014 7:55 am

siai47 wrote:The actual capacity test involves a complete discharge of the pack while connected to the M.U.T. III and takes several hours to complete. I don't know if a successful full test resets the BMU's calculation or not.
Yes. I saw that capacity test in the service manual also. It involves connecting the scan tool, selecting "Traction Battery Capacity Automatic Measurement", and turning on the car's air conditioner while the car charges to full.

From the Warranty and Maintenance Manual Addendum:
"As a result of improved software, check main drive lithium-ion battery for capacity has been eliminated from the regular and severe maintenance schedule."

I was wondering if the improved software helped to calibrate the battery capacity number, so that this longer test was not necessary.
”Red” - 2018 Red Dual Motor All-Wheel Drive Tesla Model 3 - 11/27/18
“Blue” - 2018 Kinetic Blue Chevy Bolt Premier with QC - 5/13/18
"Purple" - 2012 Raspberry Metallic ES with QC - 4/10/2013

jsantala
Posts: 296
Joined: Fri Sep 12, 2014 9:32 pm
Location: Finland
Contact: Website

Re: Canion Battery Readings

Mon Dec 15, 2014 3:41 am

It's not really that hard to determine your current battery capacity.

Connect OBDLink dongle and fire up the Canion Android app. Fully charge to 100% SOC and drive until the car doesn't move. Check the Wh out on Canion. That's your absolutely maximum usable battery capacity as measured by the car. How you drive or what you use during the drive makes no difference. Temperature will, so do this as near to room temperature as possible.

If you don't want to drive to empty, note Canion SOC % state, drive for as long as you like, note Canion SOC % and Wh out. Divide Wh out with percentage of battery SOC % lost during the drive and multiply by 100. That is the capacity of the car battery as calculated by the car at that moment. It's not as accurate as the first method, but not nearly as troublesome either. Also it doesn't put extra stress on your pack.
kWsaki.com / EVs: Nissan Leaf 2012, Citroën Xsara 1997 (conv. 81V & 8" Series DC) and Kawasaki GPX750R 1987 (conv. 87V & ME1003 PMDC) / Used to have a Citroën C-Zero 2011

JoeS
Site Moderator
Posts: 3892
Joined: Thu Dec 15, 2011 5:47 am
Location: Silicon Valley, California

Re: Canion Battery Readings

Mon Dec 15, 2014 9:39 am

jsantala wrote:If you don't want to drive to empty, note Canion SOC % state, drive for as long as you like, note Canion SOC % and Wh out. Divide Wh out with percentage of battery SOC % lost during the drive and multiply by 100. That is the capacity of the car battery as calculated by the car at that moment. It's not as accurate as the first method, but not nearly as troublesome either. Also it doesn't put extra stress on your pack.
jsantala, thank you for this concise explanation of a very simple technique for deriving battery capacity as calculated by the car.

Although I suspect the information is buried in CaniOn's data files which could be uploaded to a computer (I only did a CaniOn file transfer once a long time ago), a simple manual-entry table on a piece of paper should suffice. In addition to Date, SoC%, WhOut, Pack Voltage, and Ambient Temperature, and then calculation fields for ∆SOC%, ∆WhOut, and finally kWh. Anything else for such a table? ... or should I stop being a Luddite and import those Canion files into my Mac and then parse them and manipulate them in a spreadsheet? :geek:

I expect to take such data over a period of days?, weeks? months? on each of my two i-MiEVs and then try to figure out what it tells me about each car. :roll: :geek: Anyone have any thoughts or critiques?
EVs: 2 Wht/Blu SE Prem., '13 Tesla MS85, 3 156v CorbinSparrows (2 Li-ion), 24v EcoScoot(LiFePO4)
EV Conv: 156v '86 Ram PU, 144v '65 Saab 96
Hybrids: 48v1kW bike
ICE: '88 Isuzu Trooper. Mothballed: '67 Saab (orig.owner), '76 MBZ L206D RHD RV

Malm
Posts: 449
Joined: Mon Jul 22, 2013 12:16 pm
Location: Tábua - Portugal

Re: Canion Battery Readings

Mon Dec 15, 2014 2:58 pm

jsantala wrote: If you don't want to drive to empty, note Canion SOC % state, drive for as long as you like, note Canion SOC % and Wh out. Divide Wh out with percentage of battery SOC % lost during the drive and multiply by 100. That is the capacity of the car battery as calculated by the car at that moment.


The real limit that makes the car to stop is 2,75 V in one cell. My car reach that value in the past showing 14,5% SoC. So, unless 2,75V in one cell and 0,0% SoC happen simultaneously, the value obtained will not be the true capacity.

In my last measurements done without special tricks, my car stops with 0,0% SoC and voltage in every cells above 2,75V (but not much), so I can say that capacity measured by that method will be less then the real one. And more, 100% SoC is not the same voltage every time, at least for me.

For me, undoubtedly, capacity should be taken from 4,105 V in every cell and discharging to 2,75V in one cell. That can or not be the same as going from the 100% to 0,0% SoC, as calculated by the car.

I also think that the i-MiEV don't change is measured capacity every day. I think that is wise, because that can change significantly with battery temperature. It waits some time to get a number on its real capacity. The Nissan Leaf, on the other way, gets the number every time and do a calibration of is real capacity every day, I think.
Riding an i-Miev since 4/2011 in Portugal, 100.000 kms.

JoeS
Site Moderator
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Location: Silicon Valley, California

Re: Canion Battery Readings

Mon Dec 15, 2014 3:53 pm

Malm, I am attempting protect my pack and avoid depleting it, which is why I liked jsantala's approach of ∆SoC% and ∆kWhOut readings in lieu of the full-discharge technique.

Yes, one cell hitting 2.75v is effectively the lower limit of that pack's capacity, no matter what the SoC% readout says. Would we not expect the i-MiEV to recognize that the first time it sees this and then recalibrate its capacity?

Malm, you have been looking at these details a lot longer than I have. I'll start accumulating data and see if there is any pattern; for example, to see if the ratio ∆SoC% / ∆kWhOut is constant at various SoC levels. I've whipped up a quick form to fill in the blanks and hope to start using it despite all the distracting Christmas obligations… :geek:
EVs: 2 Wht/Blu SE Prem., '13 Tesla MS85, 3 156v CorbinSparrows (2 Li-ion), 24v EcoScoot(LiFePO4)
EV Conv: 156v '86 Ram PU, 144v '65 Saab 96
Hybrids: 48v1kW bike
ICE: '88 Isuzu Trooper. Mothballed: '67 Saab (orig.owner), '76 MBZ L206D RHD RV

Pier
Posts: 51
Joined: Tue Nov 15, 2011 9:01 am
Location: St-Aubert, Qc,

Re: Canion Battery Readings

Mon Dec 15, 2014 5:09 pm

Bobakka, here in Canada, Warranty is probably the same as US W. It says «« Main drive li-ion battery is covered for defects in material for 8 years or 160,000 km. ... Gradual capacity loss of Main bat. based on time and usage is NOT covered under warranty. See owner's manual for more info »» In owner's manual it says «« MM estimates that after 5 years, the capacity of the main drive Li bat will be approximately 80% of the original capacity. After 10 years , the capacity should be approx. 70% of original... These are only estimates....»».

So no warranty other than defect in materials. A defective cell is about all we can count on for battery replacement. Otherwise, they have the only authority to decide whether or not it is a defect or misuse by owner.

Jsantala, you are right, driving until empty is the way to see the actual battery capacity, the only capacity that counts for range. But this is not the real intrinsic capacity of the pack. And the computer changes the apparent capacity with time.

For example, my old pack (2 years old) had, from 100% Soc to turtle (10% Soc), most of times in summer, 13.400 kwh. My new pack had on first charge, only 12.000 kwh down to 10%.(around freezing point). I am on my 3rd charge now and it seems to improve. I will tell after more testing.

JoeS, I measured how many watt by 1% Soc I get in a complete discharge. It was 131 watt / 1% soc. But to my surprise, the next charge gave on half discharge 152 watt / 1% soc. I am still trying to figure out what is happening . I will do more test in the coming weeks.

Pier

jsantala
Posts: 296
Joined: Fri Sep 12, 2014 9:32 pm
Location: Finland
Contact: Website

Re: Canion Battery Readings

Tue Dec 16, 2014 12:23 am

Capacity of a lithium battery pack is an elusive thing. You can charge the same number of cells to different voltages and different cutoff amps. For example Nissan charges similar cells to around 4.2 V while Mitsu only does 4.1 V. Just a difference in temperature will also change the end result.

I have LiFePO4 packs in my DIY electric motorcycle and my DIY electric car. I could charge them quite a few ways to get different maximum capacities. I choose to charge only to 3.5 V per cell on average to extend the life of the cells. It gets me a certain number of Wh in and out.

My point is that in the end the only thing that counts is how many Wh you get out after you've charged to whatever the charging system in your vehicle considers 100% SOC and how long it lets you drive. That's the only Wh that really counts.

It is true that the SOC meter needs to be well calibrated to get an accurate reading with the simple method (not driving to 0%). If you never get down to turtle or at least the last bar flashing, your SOC calibration can be way off and your readings inaccurate. It might not be a bad idea to drive down to last few bars occasionally, if you'd like to avoid any nasty suprises when you go on that road trip.
kWsaki.com / EVs: Nissan Leaf 2012, Citroën Xsara 1997 (conv. 81V & 8" Series DC) and Kawasaki GPX750R 1987 (conv. 87V & ME1003 PMDC) / Used to have a Citroën C-Zero 2011

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