Bjron wrote:Czero get amps down very fast compared to miev. Guess its total much worst BMS on czero...
Bjron wrote:Miev was 70a until 70%. Czero is just 40a on 70%... But Fortum likes its 0.20cent/minute payment..
The BMS in the C-Zero is identical to that in the i-Miev. The difference you will be noting will be due to either differences in cell temperatures (did you test at the same cell temperatures ?) or difference in the health of the cells.
Maximum charge speed will occur at about 25-35C cell temperature, any colder than 25C and rapid charging will be slower and taper off earlier.
Also, if you have any cells with high internal resistance rapid charging speeds will be dramatically reduced and tapering of the charge rate will start very early even when the cells are at the ideal temperature.
My car now has two cells with high internal resistance and rapid charging speeds are much slower than they were two years ago. Previously it would charge at a full 43kW up to about 50% SoC before gradually tapering back, and could get from 20% to 80% in about 20 minutes.
Now even if I plug it in at 20% SoC with optimal cell temperatures it will only charge at 43kW for under a minute before it starts tapering the charge rate and it within a couple of minutes it will pull back to about 30kW. By 40% SoC it will be down to about 25kW. Charge time from 20% to 80% is now more like 30 minutes with the latter half of the charging time being very slow.
This is because the two cells with high resistance reach the maximum 4.1 volts within a minute of starting the charge even while all the other cells are still only at 4.075 volts.
So I would say the difference between your two cars is that the one that is slow to charge will have one or more cells with high internal resistance. Not much that can be done about that apart from replacing the cells, which I'm considering on mine.