Easy tracking ZEV consumption



One of the challenges in driving and managing an EV is tracking usage. Although I have a 'petrol gauge' which tracks capacity, there are more questions to answer: Have I driven better than average today? What is my rolling estimate for distance per full charge?  

Of course we all have rules of thumb (eg charging recovers about 20% an hour, since it takes 4 hrs charging from 80% discharge) and these simplify planning individual journeys without stressing. As I have said before, you just get used to doing it without any great thinking. Nevertheless it is great to have some details when you want them. So questions like What is my cost/km over a year? How long 'til I run out of power? How long to recharge if I start now? and so on. 

I keep track of the ZEV240 power usage with a small monthly Excel-compatible spreadsheet in my iPhone.  Each trip, we enter the date and trip data into three coloured columns - they are the brown, pink and yellow columns above - namely the mileage since last recharge (trip meter), the battery state (fuel gauge) and the full odometer reading. 

Once this data is entered, the sheet cacluates figures like 'km left at that usage rate', 'hours to recharge' and also cross-checks that the km travelled match the km recorded in this trip, so missed trips can be identified early.

There are also three summary blocks at the end recording:

  • The average, max and min figures for distance, power used in that month
  • The summary of total distances travelled, all power used in the month, the average rate of power use (eg 188W/km) the cost per km (eg 1.9c/km), along with daily figures like avg cost per day (eg 47c/day) and avg km per day (eg 24.7km/day), and 
  • Unique data like whether the daily trips total matches the odo reading, the number of times the battery pack fell below 20% or 30% (eg 0) and so on.


The best part is that this sheet imports into Excel and I can manipulate, amalgamate, graph etc any data I choose, as well as assemble major summaries and keep backups. 

How do you recommend people track their EV's power usage and overall performance? Any improvements you suggest?

© bdc 2014