matija
Posts: 4
Joined: Sat Nov 11, 2017 10:48 am

measuring capacity loss through CanIon

Sat Nov 11, 2017 11:05 am

Greetings everyone,

I have recently noticed that cani0n is now showing the Ah value of our battery modules. This raises few questions.

What is the new value of our Yuasa LEV50 cells ? They are branded as 50Ah. I doubt cani0n would really show 50 in brand new car. But if it would that means I have lost nearly 30% as cani0n shows 35.25Ah for me.

Although 50Ah * 88 cells * 3.7 nominal voltage does return 16kWh value.

Does anyone know how to re-initiate reading of Ah in cani0n ? This measurement was done when battery was cold and not full (14°C, 82% SoC)

I've read a lot of how voltage works in those cells, how newer cars can get 0% soc at quite high voltage (like Malm getting it at 3.6V), while older packs could go near the 2.75V limit. How SoC loss is compensated with shrinking the "turtle range", etc.

So, perhaps new car would return 50Ah to cani0n. If that is true, perhaps with BMS allowing to discharge cells deeper and deeper as they age, actually represent almost no visible SoC loss to users ?

I would love to hear others opinion.



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Aerowhatt
Posts: 336
Joined: Wed Jan 28, 2015 1:52 pm
Location: Albuquerque NM

Re: measuring capacity loss through CanIon

Thu Nov 16, 2017 1:04 pm

It’s cool that the update is showing this info since EVbatmon is such a PIA.

That’s correct that Mitsu hid part of the battery capacity from us to basically eliminate any user sense of battery degradation. Brilliant really, since degradation is kind of steep at first and then slows. Basically if you use the car as intended (never seeing turtle or running down to the bone). You would never know from the dash that the capacity was slowly decreasing. In doing so they also make the battery last longer by designating the “bottom” above the actual bottom.

I don’t recall anyone with reading above 47 ah for these battery cells. Manufacturer specs are a slow discharge under ideal conditions. Certainly not what happens in an EV!

It looks to me like it is the “calibration charge” which returns this info to the system. The three dates shown on my canion read out, all coincide with trips to the mountains followed by an uninterrupted charge to 100%.

The history panes in canion can be a bit misleading since they are disconnected in time from the current summary list on the left of the screen.

Aerowhatt
2014 cool silver ES, acquired new 4/2015
2014 Labrador Black Pearl ES, acquired new 3/2016

matija
Posts: 4
Joined: Sat Nov 11, 2017 10:48 am

Re: measuring capacity loss through CanIon

Sun Nov 19, 2017 10:46 am

Interesting read. I’m wondering though, what’s tte Ah value read by cani0n on new i-miev. Or, from which value downwards would one start noticing range drop?

I know that I do not notice quarter drop in range, although numbers suggest it - 35.5Ah / 47Ah = ~75% SoH.

Aerowhatt
Posts: 336
Joined: Wed Jan 28, 2015 1:52 pm
Location: Albuquerque NM

Re: measuring capacity loss through CanIon

Sun Nov 19, 2017 10:54 am

matija wrote:Does anyone know how to re-initiate reading of Ah in cani0n ?


So this is interesting. I had set my iMiev to charge in the early morning hours of Saturday on Friday evening. Apparently I got some food poisoning and spent most of Saturday down for the count :( . As a result the car charged as scheduled and was left plugged in until late Saturday night. During that period it returned two new AH and temperature readings for the pack on the Ah screen of canion. So triggering a new reading is not only as I had guessed. Since it also recorded one when fully charged and left plugged in all day. I have caught both of our cars re-connecting with the EVSE for a few minutes, hours after completing their witching hour charge cycles, While I was fiddling about in the garage in the morning before unplugging them. I'm assuming that is what happened yesterday some time since the first reading was a bit lower reading than the second one was.

Aerowhatt
2014 cool silver ES, acquired new 4/2015
2014 Labrador Black Pearl ES, acquired new 3/2016

matija
Posts: 4
Joined: Sat Nov 11, 2017 10:48 am

Re: measuring capacity loss through CanIon

Mon Nov 20, 2017 11:49 am

Will definately try this, with external power source for mobile device that runs cani0n. Although, I believe reading at low temperature numbers are not in favor of getting high Ah readings. Just had my battery at 2°C this morning.

Somehow I got new reading though, it was 35.25Ah at even lower temperature. I'm wondering what numbers will pop up in the spring. And I'm still thinking what do compare those readings to. 42Ah, 47Ah, or is it perhaps dynamic, just with lower reserved margin of the battery.

rnlcarlov
Posts: 48
Joined: Wed Apr 13, 2016 8:30 am

Re: measuring capacity loss through CanIon

Wed Nov 22, 2017 7:49 am

EvBatMon has shown Ah for a while now. It considers 48Ah as 0% degradation.

Aerowhatt
Posts: 336
Joined: Wed Jan 28, 2015 1:52 pm
Location: Albuquerque NM

Re: measuring capacity loss through CanIon

Thu Nov 23, 2017 2:57 pm

rnlcarlov wrote:EvBatMon has shown Ah for a while now. It considers 48Ah as 0% degradation.


I wish there were more info available from Mitsu on this subject. I don't have any faith in EvBatMon or the accuracy, origin, or viability any parameters it sets.

Aerowhatt
2014 cool silver ES, acquired new 4/2015
2014 Labrador Black Pearl ES, acquired new 3/2016

Aerowhatt
Posts: 336
Joined: Wed Jan 28, 2015 1:52 pm
Location: Albuquerque NM

Re: measuring capacity loss through CanIon

Thu Nov 23, 2017 3:00 pm

So I had another deep discharge and full recharge but no new Ah value was added to the vehicle log. Perhaps it is just periodic in nature when the system records a value??

Aerowhatt
2014 cool silver ES, acquired new 4/2015
2014 Labrador Black Pearl ES, acquired new 3/2016

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