Driving to work for a week costs less than 16 Cents!

I decided to log the energy and power used for the electricfly for a whole ten trips, 5 to work and 5 to home, and see what was the total energy used! So, for the Week of May 4th to May 8th, I logged the power data on the Woodward enhance paktrakr display with SD card, so I could take each days worth of data and analyse it, then tally it all for the week, compared to the charge afterwords.

The State of Charge (SOC) ran from 100% on the PakTrakr Display (and the Woodward Paktraker Display) at the start of the test, to 52% SOC at the end of the test, however - the battery chargers indicated between 75% SOC and 85% SOC on start up in the battery condition test mode! So - this either means they chargers are optimistic of the batteries energy capacity or the PakTrakr is more pessimistic in its analysis of the battery condition. It also means that when the PakTrakr says the pack is at 20% SOC, I would hopefully have not totally drained the Batteries, and have some safe reserve to maintain their life.

The Average Watt Hours per Kilometer (Wh/Km) ranged from a minimum of 78.21 to a maximum of 193.97 for the week. The Total logged energy used was 1,002 Watt Hours, or 1.002 kWh, while the power used in the 5 hour 50 minute recharge time (It continues in float mode when charged, and I did not check it at any regular interval, so it might have been charged in 2- 3 hours!), was 1.23 kWh according to my energy meter (UPM EM100, from Canadian Tire), for a actual energy efficiency of 81.47%, and a total energy cost at a net rate of 12.7 Cents per kWh equals fifteen point six two Cents ($0.1562) or - less than sixteen cents to drive to work for a week!

While it is true that I live very close to work, just an average drive for the week of 0.92 kms each way or a total of 9.2 kms for the week, the idea is connected to theis next couple of ideas: How much super capacitor capacity would I need for my actual drive to work, best and worst cases, and - would four, 15 Watt Solar Panels (1 amp each) produce enough power for my drive to work and still maintain or recharge the energy used in my drive to work, given the amount of sun available to them usually?

A Short look at the supercapacitor equation is based on the Watt-Seconds or Joules of energy used in my drive to work and home. This comes out to a peak used watt seconds per second of 20,690 and a maximum of 642,415 Watt Seconds or Joules for the full drive to work or home. Of course - the minimum was less, at just 259,044 Watt Seconds or Joules, with a typical value between 280,000 to 380,000 Watt Seconds per trip.

Why use or consider this idea? Well - as the Lead-Acid (PbA) Batteries are really so poor at large loads, and long runs at large loads, this gives a buffer for the acceleration currents needed, and the PbA's can slowly back fill the SuperCap's before and after a drive run so as to have better drive performance, and better battery life.

For Example Minimum Voltages on each Battery for the week, B1=9.1V, B2=3.0V, B3=8.6V, B4=9.1V, B5=8.1V, B6=8.6V, B7=8.2V, and B8=8.7V. Keeping in mind a minimum Voltage of 10.5 Volts, it can be seen that each battery ran below the minimum Voltage, and Battery #2 was the worst, with a Drop to 3.0 Volts at one point under load. Luckily, the BattEQ Eaualizers brought it back up to a good voltage for the next run, but it still dropped down to 6.3 Volts during that run (Going Home on Friday).