Category Archives: Charging


A few days ago I noticed during my car’s preconditioning that the plug to the charger was getting a bit warm to the touch. Our weather has been pretty mild recently which means that the precondition to 72F shouldn’t be using that much current–just a bit to run the fans, especially near the end of the precondition time. This is very odd since the plug wouldn’t get warm at all back in January when it was <0F out and was preconditioning to 85F.

This warmth raised a red flag in my mind: A similar thing had happened to my coworker. I haven’t mentioned him in a while–the same one with the battery problems at the plant before his car was even delivered. What had happened to him: Over the course of a few weeks his EVSE plug would get warmer with each charge until it eventually got so warm he couldn’t touch it and it was melting the connector on the vehicle side. At the time there was no clear indication if the heat was coming from the vehicle side of the connector or the charger plug. His Ford dealer replaced the car side plug under warranty but the heat and melting continued. This lead to the conclusion that the problem was the EVSE’s plug. Replacing the EVSE solved the heat problem.
Melted Vehicle connector

The reason that I’m a bit concerned about my charger is that we both had the Bosch PowerXPress EVSE installed as part of the deal with our electricity supplier. This unit has various current settings and can be setup for 16A (its default setting for the Volt) all the way up to 30A for cars with quicker chargers. We both had ours setup for 30A service. So far to date mine has never exhibited any kind of heat issue. Looks like I’ll be looking for a new EVSE–been looking for a portable solution for a while and that Clipper Creek LCS-25 looks like a really nice solution.


Win one for the Zipper…

Detroit really is a sports city: There are few other alternatives for entertainment other than movies, the occasional concert, travelling shows (Stomp, Mythbusters, etc.) and the rare play that makes its way here. Above all Detroiters love their sports teams (yes, even the Lions!). What better thing to do on a Sunday night, then take a trip downtown to see a Red Wings game.
Go Wings

Joe Louis arena, where they play, is right next to Cobo Hall where the North American International Auto Show was held. This proximity also makes the same parking structure/chargers convenient to going to Red Wings games as well.
Chargepoint map
(The blue “C” on W Congress St.)
Instead of turning left when leaving the parking structure to walk to Cobo you turn right and climb the ramps up to the arena.

Reading online about areas with a lot of EV adoption (Los Angeles, San Francisco, Atlanta) gives you the impression that there are more EV’s than public chargers can accommodate. Looking at the map above ~10 chargers are available in the dozen or so block area. Joe Louis arena seats approximately 20,000 people and these days is usually about 1/2 full. Given that EV adoption is a few percent of overall vehicle sales you’d think that there would be 10 to 20 plug-in vehicles attending any Red Wings game.

Knowing the above, we left plenty early to get to the game in order to snag one of the two spots at the Millennium Garage. Turns out I didn’t have to do so: The other charge spot remained free throughout the duration of the game. I guess the intersection of Red Wings fans and plug-in vehicle drivers is exactly one: me!
Chargepoint map
Further evidence of this was the large group of people ahead of us as we exited the arena and entered the parking garage. As they rounded the corner in the garage and saw my car I could hear one of the party loudly exclaim: “ELECTRIC!” (She said it very loudly almost shouting it).
When we made the trip down to the auto show it was a very cold January morning with a strong headwind for the ride home causing us to burn 22 kWh:
Trip Display
For this trip the temperature was a bit warmer (in the 30s instead of the 20s LOL) with very little wind resulting in us only using 20.5 kWh:
Trip Display
For some additional figures I reset the 2nd trip meter before returning home: This way I can break out the two trips:
Trip Display
The trip down to the arena used 9.1 kWh and the trip home used 11.4 kWh. On the way to the arena I was driving very conservatively, using minimal heat, etc. since I didn’t know if I could charge at the game or not. For the drive home I was free to use as much heat and speed as I wanted.
In addition, since the car was charged up when I started, I charged to full in the parking garage, and the charge station was a Chargepoint station I can also use this to calculate the efficiency of the charger in the FFE. According to Chargepoint the car consumed 10.887 kWh during that session. Thus the efficiency should be at least 83%. I say at least because I had remote started the car when the game ended so that the car would be nice and warm by the time we got there which means some of the 10.887 kWh was used to heat up the car for the 15 minutes or so it took us to get there.
In the end, though, the Wings lost in overtime. Although not the best outcome they still did get 1 point to try to keep the playoff dream alive…

Extending your range?

I’ve seen a few people post ideas in the FFE forums about how to pull a generator behind your EV to give you that extra bit of range. It is an interesting thought…enough of one that someone actually designed a thing: I give you the EP Tender (here is their main website).
EP Tender
I don’t think this guy will work for my beloved Focus Electric because he taps into the vehicle between the charger and the battery (since most EVs don’t allow charging while driving). It basically turns your EV into a PHEV with a cute little trailer. Even more fascinating is the simple solution to backing up (watch the video).


How to charge?

Chargepoint just recently redid their website. Included with the refresh is this fancy video on how to charge:

I see a few posts now and then in the plugshare app where people aren’t familiar with how to turn on/off a chargepoint station. It really isn’t that difficult, although I learned something watching it: Typically I just unplug the car when I’m done–instead of turning off the station first (it would probably complain less if I did turn it off first! LOL).


Electricity consumption for November…

Just found out I can download my meter readings from my electricity provider as an Excel spreadsheet. In addition, the readings data is down to the hour. As a result I can produce pretty graphs like this: My Focus Electric’s electricity usage for the month of November:
Pretty Graph

My total electricity from 11/1 through 11/30 was 393 kWh. Since I have the car scheduled to charge up at night you can see from the above that the vast majority of that charging happened between 12am and 12pm. The largest single charge was 13 kWh and the largest hourly charge was 7.08. Now this 7.08 figure is interesting as the car only has a 6.6 kWh charger. Thus it can be deduced that the extra 0.48 kWh is overhead due to the EVSE and internal car inefficiencies.

Another pretty graph: This one is the daily electricity usage per hour average, and maximum:
Pretty Graph #2

Note the peaks at 2:00 am and at 7:00 am in the average data set. The 2:00 am peak is due to value charging (timed charging) and the 7:00 am peak is due to the car preconditioning itself for my morning commute. This data being in November the precondition is taking a lot of power to heat up the car and melt some snow. I’ll have to post some summer data–that shouldn’t have the 7:00 am spike.

The max peaks pretty much just indicate that at some point throughout the month I’ve charged at those times (the max peaks during the day would be weekend charges).



Long trip planning, the Tesla way…or is it the EV way?

I found this article quite interesting for a few reasons (take some time to go read it…I’ll wait):

  • The current lack of Tesla Super Chargers on the east coast forces the driver to plan a bit more–like having a Focus Electric, or a Leaf (or any other <100 mile range BEV)
  • The driver comes to the conclusion at the end that is better to be more efficient than to rush (determining that driving slower and using less electricity actually saves time in the long run)
  • His reported “burn rate” for electricity is really not much higher than the FFE “burns” (300+ Wh/mile in the cold with the heater running, ~270 Wh/mile in milder conditions without heat from the article).

The ability to quick charge the Tesla does make for a much nicer experience when taking a long drive. In the above article he gets 190+ miles for 45 minutes of charge–short enough that a simple stop for dinner fills it up. I certainly hope that the next generation of EVs (FFE included) has a provision for fast charging (the J1772 Combo Plug option is already available on the Chevy Spark, and Ford has pledged to support it on future BEV and PHEV vehicles).


Some numbers on the cold

Last night I took some data down on how much electricity the car used overnight while charging (should have done this in the summer months as well!).

To start with I recorded my power usage for the day (at least what the car thought it was using, this value corresponded with 59% of the battery remaining):
Trip meter display

These numbers are somewhat typical for my daily commute. Ironically this commute was on a rather cold day with just under 1/4″ of snowfall overnight. Preconditioning the car combined with everyone’s cautious driving caused me to only use 7.2kWh of electricity! These past few cold days I’ve been using closer to 8kWh of electricity for my 31 mile commute.

Right when I arrived home I grabbed my meter reading (the car’s EVSE has its own meter):
Meter reading 1

At the time I plugged it in the outside temperature was 35F and thus the car stated “Waiting to charge” with my normal start time of 1:00am. As the evening went on the temperature dropped–when it hit freezing the car switched from waiting until 1:00am to waiting to start at the current time–it was starting its warming/trickle charge cycle.
This morning I recorded the meter right before driving away (with no preconditioning, outside temp: 20F):
Meter reading 2

So overnight the car used a total of 10kWh to keep itself warm, and charge up to 100%. Thus 7.2kWh of that went into the battery along with some burned up in the charger due to the charging efficiency (according to the EPA charging efficiency is roughly 80%) which would be about 2kWh. This leaves about 1 kWh used overnight to keep the car warm. (I’m being purposely vague here because I don’t know the exact efficiency of my EVSE + car combination. Doing the math directly yields 1.36 kWh which is close enough to my 1 kWh value.)

The numbers above align rather nicely with the daily average power consumption reported by my electricity provider. The daily averages per month also seem to be reflecting the additional power usage as the temperatures drop:

  • September: 9.9 kWh/day
  • October: 10.1 kWh/day
  • November: 12.8 kWh/day

Around here the temperatures took a dive in November which is reflected in the numbers. There are other factors in those numbers as well: In September and early October we were driving around a bit more each day due to various school/sporting activities (which may be the reason that there is only a 0.2 difference between September and October).

At this point, with our early blast of arctic air, I’ve been very pleased with the performance of the FFE–I was expecting a much greater drop in total range as an affect of cold weather.

Update: Power required for a precondition. Prior to driving the car across town for Thanksgiving I had set it up to precondition to 85F. This was the perfect opportunity to measure how much that takes. Before the car started the meter looked like this:
Power meter
Just before leaving I grabbed a picture of the meter (when the car was done preconditioning):
Power meter
Thus the car used about 5kWh of electricity to warm itself up from the ambient 25F.


Does the car charge to keep warm?

This past weekend I’ve noticed something kind of odd with my Focus Electric. The temperatures around here have been in the 20s; I keep the car parked outside (and, unfortunately, this time of year it is mostly in the shade all day too).

When I’ve plugged it in after a drive I’ve noticed it taking a very slight charge–not quite the large charge that the Level 2 can deliver (typically I see 1/2 the battery charged in 90 minutes). Today I monitored it for almost 5 hours after taking a short 15 mile drive this morning using up about 4 kWh of electricity.

Over that 5 hours of time the car consumed 3 kWh of electricity and the car did charge up to 96% charge (when it started it was somewhere around 80%). All this time the dash and the website indicated that the car was waiting to charge (its set to always wait until 1:00am to begin charging).

From this (granted not very scientific) experiment I’m suspecting that when the car needs to turn on the TMS it also turns on the charger to trickle charge the battery (perhaps even using the process of charging to heat the battery??). Very interesting indeed.

Note in the summer when I’ve monitored the car while it was waiting to charge the % charge remaining value always stayed the same over the course of the day (didn’t think to measure the power consumption at the meter though) so something different is happening when the car is cold.


New ChargePoint milestone

ChargePoint has announced that it is up to 50,000 members.

According to them the 50,000th member is a Tesla Model S owner from the bay area. This is good news: The more people sign up for ChargePoint the more likely the network will be around for a while. In Southeastern Michigan the largest network of public stations is with the ChargePoint network so you can see why I’m happy for their success.


Electrons for everyone…part 2

Recargo has a really nice infographic showing the state of charge stations in the US in 2011, 2012, and 2013. Take a look; its pretty interesting.