Category Archives: Winter Driving

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.


Staying warm…

A common problem for EV drivers is staying warm in the winter. Everyone attempts to reduce their electricity consumption in order to increase the range. As the weather gets colder out you run the heater more and more. The heater in an EV can be the most inefficient item in the car (at least it is in the Focus Electric, I hear the latest incarnations of the Leaf use a heat pump which is much more efficient–more like the A/C compressor instead of just running current through a wire). In any case you want to use as little heat as possible…

One solution is to bring along a blanket and wrap your legs up. Even better is this 12V Heating blanket. From the web page it looks like it consumes about 50 watts–much much lower than the Focus Electric’s heating element…
12V Heated blanket