PV1
Site Moderator
Posts: 3055
Joined: Fri Apr 27, 2012 4:22 pm
Location: Pittsburgh, PA

Re: EVBatMon Readings

Wed Jul 13, 2016 6:51 am

Did a 143 mile trip yesterday. Drove 10 miles, topped off on level 1, then all highway driving with AC into the pack the rest of the day. Did two quick charges, first to 92% and second to 98% (QC bottomed out at 5 amps then shut down). Two cells peaked at 106 F briefly.

What does this have to do with EVBatMon? I got home with two bars and did a full recharge. I now have 45.1 Ah of capacity! This is up from 44.4 Ah. I drove 6.9 miles before losing the top bar (a record for the particular route I drove to work this morning).

So, it pays to do a calibration charge a couple of times between winter and summer.
"Bear" - 2012 Diamond White Pearl ES with QC - 2/21/2013
"Koorz" - 2012 Cool Silver Metallic ES with QC - 1/5/2015
"Photon" - 2017 Bolt EV LT in Orange with QC - 7/31/2017

Solar-powered since 10/10/2013

mdbuilder
Posts: 228
Joined: Wed May 18, 2016 6:05 am
Location: Great Mills, Md.

Re: EVBatMon Readings

Mon Jul 18, 2016 4:58 pm

Calibration charge for me as well last night. Went from 39.6 or .4, I forget, to 40.1 :D Feels better being over 40 ah for some reason ;)
2015 Nissan NV200
2012 I-Miev SE Premium
2009 Mazda 5
2017 Toyota Prius Prime

tinoale
Posts: 39
Joined: Wed Apr 23, 2014 6:36 am

Re: EVBatMon Readings

Sat Jul 23, 2016 12:55 pm

Just got my first reading :
2012 C-zero (16kWh version), 55k km, 37.1Ah left, 77.29 PMC

Considering how little range I have actually lost, I cannot believe it was 48Ah when I got it new, no way.
Without the data points, I'll never know.
I an wondering though if the car doesn't store some kind of history somewhere in it's memory. Would be awesome to be able to pull it out.

Lic
Posts: 71
Joined: Mon Dec 28, 2015 2:11 pm
Location: Canada

Re: EVBatMon Readings

Thu Aug 11, 2016 4:30 pm

Lic wrote:EVBAtMon shows 37.4Ah for my 2012 i-miev (51k km)

36.9Ah (54k km) right now.

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

Re: EVBatMon Readings

Fri Aug 12, 2016 12:39 pm

tinoale wrote:Just got my first reading :
2012 C-zero (16kWh version), 55k km, 37.1Ah left, 77.29 PMC

Considering how little range I have actually lost, I cannot believe it was 48Ah when I got it new, no way.
Without the data points, I'll never know.
I an wondering though if the car doesn't store some kind of history somewhere in it's memory. Would be awesome to be able to pull it out.


You don't fill it lost all that capacity because when new the car doesn't use all its capacity (car stops with 0, 0 % Soc but with high voltage in the cell, surelly over 3,6 V). Maybe it works in the first two years as if it only has 42 Ah instead of 48. That's why we don't fill loss of capacity in the two/three first years.
In the beginning of juillet mine was at 33.2 Ah. Then, one day went to 34.2 Ah, and in 6 of August was down to 34.1 Ah. 93.000 Km in 5 years and 4 months.
Riding an i-Miev since 4/2011 in Portugal, 100.000 kms.

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

Re: EVBatMon Readings

Fri Aug 12, 2016 1:12 pm

Malm wrote:
You don't fill it lost all that capacity because when new the car doesn't use all its capacity (car stops with 0, 0 % Soc but with high voltage in the cell, surelly over 3,6 V).


Malm, you think this is the way that iMiev hides capacity in the first years?
If you are right then the CellVoltage as a function of a fixed %SoC should be an indication of real iMiev battery capacity?
For example for 17% SoC (1 bar) the CellVoltage should drop from something like 3,7V when the car is new and hiding capacity to 3,5 V when the car has shown all its capacity.
My iMiev with now 111k km show around 3,6V CellVoltage for a 17% SoC reading.
iMiev; New Feb 2011; 119000 km January 2017

PV1
Site Moderator
Posts: 3055
Joined: Fri Apr 27, 2012 4:22 pm
Location: Pittsburgh, PA

Re: EVBatMon Readings

Fri Aug 12, 2016 1:28 pm

I've seen my battery as high as 45.1 Ah. This is for a year old, LEV50n (improved cells) pack with average daytime high temperature of 90 F. The calculated capacity continually drops in .1 Ah increments, at what I believe to be each week. The car will do a re-calculation when charged to full from 2 bars or less. When I first started using EVBatMon, my Ah capacity was lower, but two calibration charges in hotter weather increased the value.

I think a new battery value of 48 Ah is a bit high. Realistically, 46 Ah should probably be considered 100% (unless someone's seen a higher value). Remember, our cars stop charge at 4.1 volts instead of 4.2, plus the margin at the bottom (which steadily decreases as the car ages).
"Bear" - 2012 Diamond White Pearl ES with QC - 2/21/2013
"Koorz" - 2012 Cool Silver Metallic ES with QC - 1/5/2015
"Photon" - 2017 Bolt EV LT in Orange with QC - 7/31/2017

Solar-powered since 10/10/2013

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

Re: EVBatMon Readings

Sat Aug 13, 2016 12:26 am

"Malm, you think this is the way that iMiev hides capacity in the first years?
If you are right then the CellVoltage as a function of a fixed %SoC should be an indication of real iMiev battery capacity?"
YES.
Riding an i-Miev since 4/2011 in Portugal, 100.000 kms.

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

Re: EVBatMon Readings

Sat Aug 13, 2016 12:39 am

My car show regularly a decrease of 0,1 Ah each 20 days.
With the higher temperatures it did a recalibration last month. Hot weather this summer, maybe the hottest one ever. Portugal is now with a significant part of its forests on fire. So, only if I had a big fridge to stop it inside I could escape to this higher temperstures. I do some refrigeration when driving, what keeps it under 40°C.

Still, after a very bad first 3 years, now with my methods os keeping the batteries at lower temperatures my degradation rates are one of the slowest of all.
Riding an i-Miev since 4/2011 in Portugal, 100.000 kms.

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

Re: EVBatMon Readings

Sat Aug 20, 2016 11:22 am

Image

34 Ah is the current capacity. It assumes that, from information obtained with time. But it is only a guess, as I show.
Riding an i-Miev since 4/2011 in Portugal, 100.000 kms.

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