Monday, 9 March 2009
First decent drive observations
First of all. What fun!
Now for some stats.
24.6km Hilly terrain
Start voltage was 657v. 100%SoC according to the greensaver battery data sheet.
End voltage was 621v. 50%SoC.
Energy used (probably) = 6kwh. Efficiency = 250Wh/km
I am mixing measurements here however, the kwh counter read 8.2kwh. This is motor energy both driven and regen. This gives 2.2kWh regen which I find very hard to believe, considering the charge efficiency will not be great.
For now I will rely on the pack voltage for SoC while stationary. I have printed out a lookup table to translate voltage into SoC.
I had the regen set for 10kW (66.6%). This gave over voltage warnings (801+ volts) and was a bit much for the batteries at 16v per cell, but did not trip on a full charge. This equates to a charge current of 12.5A. minus about .5A through the balance circuit.
I have backed this off to 8kW (53.3%) to try and minimise over voltage on the batteries.