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: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 :-)