AC Charging Speed / Efficiency

[Negue]

ps 30 mV delta at the top end is huge (excessive), hopefully it will balance out during the calibration charge, but could be a sign of a weak cell.

I discharge the battery untill heat stop.


I will do this days a 100-0-100% cycles untill values sync ...

Untill now is something odd.
Last night I charged untill 100% and at 16:00 was ~75% SoC

Cap2 was disconnect because courier called to announce if someone is home to bring my dog food :/
To bad that OBDZERO can't work in background.

 

[kiev]

You only need to do it one time for the calibration to occur.

Did the car charge up to 16 fuel bars without stopping/interruption? If not then you might have to repeat it.

But after that then check your cell voltages and report back the delta max-min voltage.

It is not possible to balance back a large delta due to the very low (100 mA) balancing currents involved, so no need to churn the pack with numerous deep discharge cycles.

Determine the delta when fully charged and when at a low SOC, that will give some good information to evaluate the state of health of your pack.

Module10 CellC looks to be very weak and way out of family

 

[MickeyS70]

I will do this days a 100-0-100% cycles untill values sync ...

This may never happen (see below)

Last night I charged untill 100% and at 16:00 was ~75% SoC

Looks like cell10 C has an intermittent CMU fault, it seem to have worked fine last night but not today?

Cap2 was disconnect because courier called to announce if someone is home to bring my dog food :/
To bad that OBDZERO can't work in background.

For best results run CAP2 on a separate device altogether, the use of a power bank is also recommended.

You only need to do it one time for the calibration to occur.

Correct, but the conservative BMU algorithm will change the capacity by +/- 1Ah max per go.

Even if you repeat the procedure multiple times, changes of only about +/- 2Ah per month are feasible.

To do this in one go, you need a to run the battery calibration function with HobDrive/MUT3/Diagbox

Even without the outlier, your pack has a huge delta (3.26/3.7V), this should improve when fully charged, but is a sure sign of many bad (low capacity) cells.

 

[Negue]

I repeat Cap1 and Cap2 but I will try again
Same thing. I had a drop of km remaining after charging. Not sure how much but I drove ~7km from 100% at evening, and in the morning had ~75% ( I remember that I lost ~7km ).
I will see if the C10 cell is still down at next test.


I drown it untill on bord km indicator show --- because winter arrived and is mismatched the km remaining (indicate 19km and drived 15.5km) and I needed other 2km to garage :/
I detour to a ChaDeMo that find it was broken and untill I grabbed Type2ToType1 adaptor, MieV had 20cm snow on it and was to risky with summer tires to drive.

Some days ago , indicate 11km and drived 11km and still indicate 1km remaining.

 

[MickeyS70]

Some days ago , indicate 11km and drived 11km and still indicate 1km remaining.

The RR is a predicted value based on current SoC and past (15 mile) consumption. It’s only accurate if you continue your journey under identical conditions (speed, elevation, temperature etc) and the actual battery capacity is matching the BMU value

 

[Negue]

After a 4kw DC and some driving, C10 died before RR drop to 0
Died at RR 2.5km

 

[MickeyS70]

After a 4kw DC and some driving, C10 died before RR drop to 0
Died at RR 2.5km

Using DC charger on an already unbalanced pack will make matters worse, at this point there isn’t much left to do other than replace the HV battery cells completely.

 

[Negue]

I have in plan to change all cells but now allready invest in cells for Leaf :/
Probably I will try to change C10 fast to use it untill I change all.

Meanwhile, I will try to find something at 120Ah ...

 

[MickeyS70]

Meanwhile, I will try to find something at 120Ah ...

Did you see this?

https://myimiev.com/threads/making-a-custom-battery-pack-for-miev.5459/post-52601

 

[Negue]

Didn't know it untill now. Tq
I will read with interest