Tuesday, October 28, 2014


After weighing the Fiero yesterday, I decided to take if for a test drive to see if my watt hours decreased. As  274 pounds of batteries were taken out of the front of the car, I was expecting the watt hours per mile to decrease around 27.4 from the 288 to around 261 watt hours per mile. To my surprise, the watt hours per mile came down to 228, using 120 volts as the average. 

When I removed the batteries, not only was the weight reduced but the front of the car came up a couple of inches, possibly changing the aerodynamics of the car. Additionally, the belly pan was removed. The other issue is what do you use as voltage when figuring how many watts you used? Before I started the drive, the voltage was around 135 volts and as the drive progressed, the voltage was slowly declining. Below is a graph that illustrates the difference in watt hours depending on what you use as the voltage.


Another factor is that the entire test drive today was in forth gear, as the shift cables are out of adjustment again. As stated above, I was expecting the watt hours per mile to decrease by around 27 watt hours but it dropped anywhere from 31 to 60, depending on the voltage I plugged in. I can see a real need for a good watt hour meter that counts up and down and gives an average watt hour reading based on samples of current and voltage.

I thought I had a log file of the drive but when I opened it, there was nothing but zeros in the accelerator voltages, so I must have actually turned it when I was sitting in the driveway.

The garage is cleared out and ready to pull the car in when the weather turns cold this weekend and I have started getting contactors and wiring ready to bottom balance the other two packs.

Thanks for dripping by,

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