Friday, June 19, 2015

Good things come of people behaving badly

Somebody must have noticed the situation at work with the level-2 electric vehicle chargers.  Lately, the EV mailing list has been fired off with regular announcements of people leaving their car in the charging spaces after they have finished charging while others practically beg for a couple of hours of connection time.  (It doesn’t help that nearly all the convenient parking is now in use too, leaving disconnecting folks limited parking options.)  People are struggling to learn the new etiquette surrounding public infrastructure sharing.  We all struggle to find an opportunity to charge, but we seldom think about our impact when we fail to disconnect and vacate the charging space in a timely manner.  Sharing is a trait acquired in one’s youth when growing up with siblings, although this can also lead to hoarding.  Fortunately, the company decided to take the next step toward being a good advocate of electric vehicle adoption.

About two weeks ago, I noticed that a number of parking spaces near the employee entrance to the building had been roped off, and digging/trenching was underway.  I followed the route (visually) of the trenching and saw that it connected to the building and up to the roof (where the solar panels are).  I asked one of the construction crew members what the project was and they said they were working on installing four new charging stations with two plugs each, producing eight new charging spaces.  Added to the existing fourteen plugs and that amounts to more than 50% more charging points for us electric vehicle drivers.  Now, as I walk past the site each evening as I leave, I admire the new stations as they await final connection in the coming days.  Soon, we won’t have to depend quite so much on everybody’s etiquette and consideration.  I can hardly wait.

Saturday, June 6, 2015

To charge, or not to charge

Anybody over the age of 30 remembers the first NiCad rechargeable batteries from the 1990’s.  These batteries needed to be depleted completely before recharging or they would “remember” how much you used and only recharge that amount in the future.  NiMH batteries got rid of the “memory” issue, but did little to improve charge capacity or battery life.  My first hand-held device had a Li-Ion battery and came with instructions to let the battery drain to 25% to 75% before recharging.  I followed that advice to a large degree and managed to get three years of useful charge from the battery before it started to dwindle.  I did not follow that advice for my laptops and those batteries all failed to hold the originally promised charge beyond two years.  With my first two cell phones, I was diligent about appropriate battery charging and managed to get more than four years of nearly full charge capability from each before the batteries started to degrade.
Five ticks remaining on the I-MiEV charge gauge (5/16)

So, before I even bought my electric car back in 2012, I knew how to better care for the battery.  Wait for the charge to drop below 75% full before recharging and avoid complete discharges when possible.  My commute usually draws the battery down to about 45% remaining, so this represents an ideal point at which to recharge the car.  But, when I know I will be working from home the next day, should I wait to charge the car or charge it right away?  The ideal choice for extended battery life (according to articles I have read) is to complete charging within an hour or two of when you expect to drive again.  The thinking here is that maintaining a full charge for an extended period strains the battery, ultimately weakening it.  But, the practical choice is to have the car ready to drive in case of an unexpected need the next day (which seldom happens for me).  So, I choose to charge at night and have the car sit fully charged the next day.

The real trouble arises when I use the car the next day to run a short errand and I use less than 25% of the battery capacity.  (Typically 85% to 90%of the charge will remain.)  Then I have to drive to work on the following day.  I admit that I like my comfort zone when it comes to the car’s range.  I don’t enjoy learning just how far I can push the car without running out.  While I can get to work and back and still have at least 25% of the charge remaining, it reigns-in my after work activities, limiting me to a short trip to a local store.  On the other hand, recharging with only 10% to 15% drawn off the battery will accelerate its decay.  When I know I need to do some extra driving I will recharge before driving to work.  When I have no plans, I drive on the reduced charge and hope for the best.  Sometimes, I have the option to charge once I get to work, which allows me to run those after-work errands.  To date, my efforts have paid off as I have lost less than 5% of the original driving range after 41 months of ownership.  (Mitsubishi warrants that 80% of the charge capacity will remain useful for ten years.)