krox
Posts: 4
Joined: Mon Apr 08, 2019 6:44 am

Re: Battery Capacity Testing

Tue Apr 09, 2019 8:41 pm

Thank you.

pbui19
Posts: 168
Joined: Tue Jan 07, 2014 12:17 pm

Re: Battery Capacity Testing

Thu Apr 11, 2019 1:49 pm

DBMandrake wrote:Canion, Hobdrive, and Evbatmon will all give the HV battery Ah capacity.

Canion is free but requires a more expensive STN11xx adaptor (such as OBDLink LX) and will not work with a cheap ELM327 adaptor.

Hobdrive has a free version and will work with a cheap ELM327 adaptor so is probably the cheapest outlay to read the battery capacity if you already have an Android device.


hi Simon,

Thought to give Hobdrive a try, as my Canion Trip screen has been blank for a while. At the first run, Hobdrive asks for make/model, which list Mitsu and not iMiev. What model do you select ? or perhaps I downloaded the incorrect apps.

For some reason, my Canion screen where the real-time Ah was display. It still shows Ah history, but roughly on a monthly interval.
Thanks for any hints.

DBMandrake
Posts: 190
Joined: Mon Mar 20, 2017 4:57 am
Location: Scotland

Re: Battery Capacity Testing

Fri Apr 12, 2019 12:46 am

pbui19 wrote:
DBMandrake wrote:Canion, Hobdrive, and Evbatmon will all give the HV battery Ah capacity.

Canion is free but requires a more expensive STN11xx adaptor (such as OBDLink LX) and will not work with a cheap ELM327 adaptor.

Hobdrive has a free version and will work with a cheap ELM327 adaptor so is probably the cheapest outlay to read the battery capacity if you already have an Android device.


hi Simon,

Thought to give Hobdrive a try, as my Canion Trip screen has been blank for a while. At the first run, Hobdrive asks for make/model, which list Mitsu and not iMiev. What model do you select ? or perhaps I downloaded the incorrect apps.

For some reason, my Canion screen where the real-time Ah was display. It still shows Ah history, but roughly on a monthly interval.
Thanks for any hints.

Hobdrive is not the easiest to use. To initially set it up, go to Screens->Settings, under OBD-II port settings to select your (already paired) bluetooth OBD adaptor.

Then go to Screens->Settings->Vehicle settings go to ECU Settings then on the right choose Mitsubishi iMiev Li-ION. Don't worry about trying to fill in the My Vehicle section - there isn't any valid choice that matches these cars.

That should get the device to connect to the car. (Remember the car needs to be on) If successfully connected the red dot in the lower left will go green.

To get the usable Ah capacity go to Screens->BMU, and the figure you're after is BMU_BatteryCurrentCapacity, which will be in Ah. This figure should match that reported by Canion. (It does for me anyway!)
- Simon

EV: 2011 Peugeot Ion
ICE: 1997 Citroen Xantia V6

pbui19
Posts: 168
Joined: Tue Jan 07, 2014 12:17 pm

Re: Battery Capacity Testing

Fri Apr 12, 2019 1:34 pm

Thank you for your instruction, I was able to get Hobdrive to work; and indeed the Ah is same value as from Canion. I did get the dreaded warning light car-with-!; but it went away upon restart.

I am glad to see the 12v-aux voltage display, is there a way to plot this voltage ? my thinking is the plot may show a voltage drag upon starting/relay engaging etc... which would indicate a weak 12-v batt.

My indicated Ah value has been dropping quite a bit these last few months; but I am not sure that my range has been affected. Have to wait for warmer weather for the reference drive.

Has anyone notice the Ah value increasing after a calibration-charge ?

-Paul

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

Re: Battery Capacity Testing

Fri Apr 12, 2019 4:46 pm

pbui19 wrote:...Has anyone notice the Ah value increasing after a calibration-charge ?
Hi Paul, yes mine went from 38.1Ah to 39.1Ah a couple of months ago after I did a long slow charge from two bars. Presently sitting at 38.9Ah. This was on the replacement battery which has about 35K miles on it. Even though I pamper my battery when charging, I'm afraid my leadfoot is not nice to it otherwise.
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

DBMandrake
Posts: 190
Joined: Mon Mar 20, 2017 4:57 am
Location: Scotland

Re: Battery Capacity Testing

Sat Apr 13, 2019 12:59 pm

pbui19 wrote:Thank you for your instruction, I was able to get Hobdrive to work; and indeed the Ah is same value as from Canion. I did get the dreaded warning light car-with-!; but it went away upon restart.

The warning light was probably caused by connecting Hobdrive to the car before you selected the ECU type. It defaults to normal OBD-II scanning using multiple protocols - this upsets these cars and sets fault codes and lights the warning light. Other apps like Torque Pro etc will cause the same issue, in fact any generic OBD-II application that is not specifically compatible with these cars.

The warning light will self reset after a power cycle and most of the fault codes will clear by themselves so its not something to worry about. Once the correct ECU is selected it won't happen again.
I am glad to see the 12v-aux voltage display, is there a way to plot this voltage ? my thinking is the plot may show a voltage drag upon starting/relay engaging etc... which would indicate a weak 12-v batt.

I don't think you can graph the voltage, at least not at a high sample rate that would show what you're looking for. You can get the 12 volt battery reading either from the EV ECU - which I'm guessing is what you're looking at, or from the actual OBD-II adaptor itself as the ELM327 protocol allows for asking the OBD adaptor itself to measure the voltage at the diagnostic socket. You can see that in the custom PID's page.
My indicated Ah value has been dropping quite a bit these last few months; but I am not sure that my range has been affected. Have to wait for warmer weather for the reference drive.

Has anyone notice the Ah value increasing after a calibration-charge ?

Not sure what you mean by a "calibration charge ?"

I've had a number of large drops in Ah capacity over the last year, documented in the following thread:

viewtopic.php?f=23&t=4014

Due to these large drops my car has gone down from 39.9Ah at 28k miles to only 35.1Ah at 51k miles. :(
- Simon

EV: 2011 Peugeot Ion
ICE: 1997 Citroen Xantia V6

pbui19
Posts: 168
Joined: Tue Jan 07, 2014 12:17 pm

Re: Battery Capacity Testing

Mon Apr 15, 2019 1:48 pm

By "calibration charge", I meant to charge from the blinking 1-2 bars to 100%. My understanding is that when the guessometer hits 2 and below bars, the BMS goes into some sort of integration mode to reset the available Ah. In fact, I don't understand how does the software calculates and reports the pack Ah without a calibration charge.

I would say in general, the pack capacity is the input Ah between the SOC when ONE cell reaches the bottom, 2.9 v ?, and ONE exceed the top at 4.10xx ? essential in between the high/low knee voltage curve.

Both Canion & Hobdrive are reported my pack at 36.9 Ah at 22Kmiles; but I can't honestly tell whether my range has diminished. It's the range that matters, not the reported Ah.

DBMandrake
Posts: 190
Joined: Mon Mar 20, 2017 4:57 am
Location: Scotland

Re: Battery Capacity Testing

Tue Apr 16, 2019 3:09 am

pbui19 wrote:By "calibration charge", I meant to charge from the blinking 1-2 bars to 100%. My understanding is that when the guessometer hits 2 and below bars, the BMS goes into some sort of integration mode to reset the available Ah. In fact, I don't understand how does the software calculates and reports the pack Ah without a calibration charge.

Yes, only a near full discharge from full or charge to full from nearly discharged gives the BMS the opportunity to measure the Ah capacity properly.

In between those few times when it can measure it it simply follows a programmed in "assumed degradation" model. If you have a look at my Ah graph You can see the shallow gradient of about 0.1Ah per 1000 miles is the programmed in degradation model. Periodically the larger drops are based on actual measurements so it can be seen that for my car the actual degradation over the full time I've owned the car is at a much greater rate than assumed by the model in the BMS...about a 3x steeper drop. (in other words Mitsi underestimated the battery degradation)
I would say in general, the pack capacity is the input Ah between the SOC when ONE cell reaches the bottom, 2.9 v ?, and ONE exceed the top at 4.10xx ? essential in between the high/low knee voltage curve.

Yes, although fully discharged (0% SoC reported in Canion and the car shutting down) is 3.63 volts per cell on my car. There is some evidence that as the batteries degrade and lose capacity, a little bit of capacity at the bottom end is "unlocked" by allowing the cells to discharge lower than 3.63 volts. But not too much lower.
Both Canion & Hobdrive are reported my pack at 36.9 Ah at 22Kmiles; but I can't honestly tell whether my range has diminished. It's the range that matters, not the reported Ah.

Mine was at 39.9Ah at 28k miles which at the time was good and seemed better than most other Ion's however after a series of large drops in reported capacity I'd say that mine is now significantly worse than most. I definitely have at least 2 weak cells that are probably responsible for most of the drop and have toyed with the idea of replacing them, however sourcing known-good second hand cells at an affordable price, and having the where with all to replace them (requiring a full day with access to a 2 post hoist) is not easy, so I'm not sure whether it's worth the trouble.

I've definitely lost range on mine - summer range has gone down from about 63 miles to 55 miles in the 2 years I've had the car, and who knows what the next 2 years have in store for me. As I can barely make my daily commute in the winter as it is now, the next two winters will be tough. I have a rapid charger to fall back on but that adds significant time and cost to the journey home.
- Simon

EV: 2011 Peugeot Ion
ICE: 1997 Citroen Xantia V6

aion
Posts: 2
Joined: Sun May 05, 2019 11:46 am

Re: Battery Capacity Testing

Sun May 05, 2019 11:52 am

Hello there "electric friends" ;)

As for using CANION or OBDRIVE is there much of a difference from one to the other? Or both can show the same info?

Thanks

Aion

pbui19
Posts: 168
Joined: Tue Jan 07, 2014 12:17 pm

Re: Battery Capacity Testing

Tue May 07, 2019 8:10 am

Image

hope the photo link can be viewed. It's the Canion Ah history screen of my 2014 since Dec 2018. I've been QCDC charging almost exclusively (to around 80% SOC) , trying to save the onboard charger. The Ah decline line worried me a bit, but it seems to correlate more less Mandrake degradation modeled 0.1Ah/1000-mile; though mine seems a bit worst.

The 0427 Ah update was from a calibration charge from 2 blinking bars using level1 EVSE. I was a little surprise to see the 0429 update, which must have happened because it was charged until stop. I was relieved to see the Ah increased; though I must admit I rarely to a cal charge.

Planning to execute another cal charge soon and hoping for another bump in Ah

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