Tuesday, August 3, 2010

500 miles at 216V

This weekend, I passed 500 miles in the Volt914 with its new 216V pack.  It is staying very well balanced - the Rudman Regulators are doing their jobs well.  And, with quite a few trips in it, I'm able to assess its efficiency at the higher voltage and with the new charger.  Take a look at the miles vs. kWh plot:
As you can see, the least-squares fit line shows that a good approximation of wall-to-wheels electricity use is a 910 Wh fixed overhead per charge, and about 280 Wh per mile.  This is wall-to-wheels, so it accounts for all the efficiency losses of the AC-DC conversion process as well as the reverse DC-AC conversion for driving.  Not too shabby!  And, much better than the old 144V floodies with the Zivan NG-3 charger, which were giving me 1,230 Wh fixed overhead per charge and 380 Wh per mile wall-to-weels efficiency (!).

Edit: Forgot to mention, at my current cost of 7.5 cents per kWh, I spent  about $14 for the electricity for those 500 miles, at an average cost of 2.8 cents per mile.  Which compares to 3.7 cents per mile with the old 144V system - a 25% reduction in cost.

Of course, I will soon be paying essentially *nothing* for the electricity my cars use:

This is a 5 kW array, which will generate about 7,000 kWh per year.  Between them, the Volt914 and the Electrojeep use about  2,000 kWh per year, if I drive both of them every work day.  Which I don't.  But I could :-)