[Ovmsdev] BUG? in v3.2.0-1 in vehicle_mitsubishi - flood of BMS-error msg

[Michael Eric Menk]

On 19.01.2019 17:38, Tamás Kovács wrote:

> Now i see your bms error message get from temperature, you can change 
> the threshold of the error messages same place as disble this messages.

You can not push out an image with a temperature warning at 2°C when 15 
- 25°C temperature difference is normal temperature difference when 
using the car.

If you look at the graph linked underneath, you will see the min and max 
temp while charging on at 125A charger. The charge is from a 1400km trip 
in -18 to -10°C outside.

You can see the cells closest to the air intake becoming colder while 
charging. Even with the active cooling, the BMS have reduced the current 
from the charger to save the warmest battery (protection starts at 31°C).

Graph: 125A amp charge in winter:
http://vedlegg.uib.no/?id=80da14370e694e5e23a9e91e8aa4df29 (link valid 
for 3 years)

You will also get the same temperature difference in the summer, but 
then the AC compressor will cool the air down.

With the high temperature difference, the battery will charge 
differently, resulting in a  imbalanced pack. Since the BMS uses 
top-charge-balancing, they will not get fully re-balanced before you 
connect onboard charger.

I recommend that you disable the BMS warning by default before pushing 
the image.

> On web interface you can see cell volt and temps in bar graps, you see 
> 88volts and temps? Can you send a photo from this page.
>
On the "cars website" I see 88 volts, but there are only 80 cells. Both 
C-Zero and Ion have for a long time used 80 cells.

I suspect that the numbers from the non-existing cells are from other cells.


__Dashboard config___

A solution for the dashboard voltage gauge is to use the battery voltage 
to set the correct min-max voltage. There is no overlap of the voltage 
of the 88cell pack and the 80 cell pack.

80 cells at 4.10V = 328.0V (target voltage while charging (CV))
80 cells at 4.12V = 329.6V (max volt)

88 cells at 3.00V = 264.0V

In order to get close to the max of the 80 cell the 88 cell pack have to 
have an average cell-volt of 2.61V, while the BMS reports in my logs 
reports 8.5%SOC at a average cell voltage of 3.09.

if (StandardMetrics.ms_v_bat_voltage->AsFloat() > 340 ) {
// set gauge for 88 cell back

} else {
//set gauge for 80 cell pack

}


>
> What program you create a log for long time?
>
>
CanIon, the OVMSv2 I got was DOA, I continued using CanIon in a "client 
server mode" while waiting for OVMSv3.

The graph above was created by:
select datetime ( s.timestamp/1000 , 'unixepoch' ) as logtime , s.odo , 
s.b_soc , s.b_amp*s.b_volt/1000 as kW ,b.mintemp, b.maxtemp , b.maxtemp 
- b.mintemp as tempdiff , s.ac_w  from seclog s left join  
view_diff_temp  b on s.timestamp/1000 = b.timestamp/1000 where s.fps > 
200 and  s.rr = 255 and s.speed=0 and s.b_amp > 0  and odo = XX;