Please find here some graphs about my first Chademo rapid Charge last summer.
I went back yesterday to try to get some missing data, last time I didn't check the DC kill A watt values at the Chademo charger,
But this recent Chademo charger was out of order, .... and also the system get aware now that my card was not a KiWhi Pass... :? http://www.kiwhipass.fr/ ,
so this was my first and may be last ever fast charge.
Anyway, this first graph below is showing how the amperage have to adapt quickly to the maximum voltage allowed.
For my Blue Lightning 88 battery cells, the soft landing is for a maximum value of 361 Volts.
In other words, the internal battery resistance and the Ohm's law, Voltage = Resistance x Amperage, can only allow a 80% charge at high amperage, otherwise, it would blow off the battery.
A longer soft landing at lower amperage could be done, but it would be time consuming.
This is also probably the reason of a Renault Zoe owner's comment, complaining this fast charger was looking for him as 22 kW-h "powerfull" instead of 44 kW-h,
http://chargemap.com/points/details/auchan-le-havre .
1-Chademo Voltage Amperage versus SoC
Below, in my opinion, the battery temperature, during a rapid charge, increases at a faster rate than at home with my "16A" Charge, but at the end of charge, temperatures are identical.
On right, the balance of the battery cells is good at the end of the fast charge
2-Chademo Temperature, Cells Balance versus SoC
On left below, energy input, following Canion SecLog data.
These values, as said before, are not true values, the line slope versus SoC give 14.68 kW-h per 100% SoC, it should be, for this 88 cells Battery, 16.28 kW-h, (Blue Lightning battery capacity) or above.
The magic correction coefficient, from other data, for me, could be the ratio 60/50, so the real DC charge would be of 0.1468 x 60/50 x 100 giving a DC input of 17.62 kW-h per 100% SoC.
With this number the fast DC charge efficiency from the plug on the car would be of 16.28 / 17.62 = 92 % which would be far better than an AC charge if the Chademo charger efficiency is forgotten.
This number might be true, as the DC Chademo charger probably by pass all this AC DC => DC AC => AC DC on board charger, http://mmc-manuals.ru/manuals/i-miev/online/Service_Manual_2011_2012/img/54/AK900546AC00ENG.pdf
A curiosity below on the right graph, during the fast charge, RR was giving a range of 255 km... Battery cell voltage stays close to 4.110 volts and does not go above this value.
3-Chademo Charge, Umax, Umin, RR, versus SoC by
Blue I.ightning
When the high amperage stops, thank to the Ohm's law, the voltage goes down, see first graph on top, so we can get a cell average internal resistance at charge.
(361Volt -358.6 Volts) / 25.08 Amperes / 88 cells x 1000 = 1.09 mOhm per Cell.
Below on the graph, this value, red point, seems to match some values given at high acceleration or deceleration, see former post.
http://myimiev.com/forum/viewtopic.php?p=17242#p17242
http://myimiev.com/forum/viewtopic.php?p=17252#p17252
http://myimiev.com/forum/viewtopic.php?p=17602#p17602
4-Chademo Average Cell Resistance versus Temperature