The GM Volt's Unique "Delayed Charging" Feature

Sunday, September 26, 2010 0 comments
Trent Warnke (Propulsion Engineer on GM Volt Team)
shows us where to plug in the Volt.
The Volt has a little known, but brilliant charging feature that solves a big future problem.  To understand why I think it's cool, you need to know a few things...

Like setting an alarm clock, most new EVs will allow you to schedule the beginning of charging your car.  This allows you to plug your car in when you get home...but only start charging the car at some time at night when the rates are cheapest.

For example, this means that most people in Pacific Gas & Electric territory will set their cars to start charging at 12am when the cheapest rates begin...since that's when rates drop in half to 5-6 cents per kilowatt.   BTW, at this price, it only costs ~$300 to fuel your car for 14,600 miles!  That's $1,690 cheaper than a gas car getting 22 MPG at $3/gallon.

However, if everyone's car started charging exactly at 12:00:00:00am, the initial surge could overstress local power grids...especially in neighborhoods with old/undersized electrical infrastructure.  This could cause local/neighborhood blackouts...and thus local hatred of people who buy electric cars...and that's never good. 

So how do you allow everyone to charge within a small time window and not stress the local grid?

© GM Corp - Delayed Charging.
You use the Volt's cool charging feature to schedule the END of that the car is fully charged by your departure time.  The Volt is smart enough to know how long it will take to recharge based on what Charging Level your Volt is plugged into, and automatically start charging when it needs.  For example, setting your Departure Time at 6:00am might cause cause your Volt to start charging at 3:37 am...because it knows you only need 2h 23m of charge at Level 2.

Since Charge Start Time depends on the how much the battery is depleted, the Charge Start Time will be fairly it's VERY doubtful that charging will start at the same time as any of your neighbor's cars.

So, you get your car charged by time you need it...and you don't contribute to any electrical problems in your  neighborhood!

Brilliant.  Now, when will the other car companies adopt this feature?

© GM Corp - The 2011 Chevrolet Volt allows owners to select
from three different charge modes, including immediately,
delayed based upon departure time and delayed based
on both rate and departure time.

Test Driving a GM Volt - The Uncompromising EV

Friday, September 24, 2010 0 comments
I was a very luckily boy last week...I got to drive a preproduction Chevy Volt and spend time talking with Britta Gross (GM, R&D and Strategic Planning on GM Volt Team) and Trent Warnke (Propulsion Engineer on GM Volt Team).  It was fun to get around two people excited to tell you all about their creation.

I gotta say, the Volt is a very impressive car...and I haven't been a fan of General Motors. 

The Volt is the most uncompromising EV on the market: it drives like a performance V6 sedan, only cost you ~$2 to go the first 40 miles, has lower maintenance than a gas car, and you can drive it across America today without having to worry about finding a charging station.

This car will win over the minds of many EV critics. 

  • It hides A LOT of complexity and works like a regular car.  Anyone who has ever designed something, knows how hard it is to make complicated things...simple.  Considering all of the technology in this car, it behaves and drives any other car, except you get these huge benefits if you charge every night...
    • Lower engine maintenance since you won't be using it much.  GM has even factored in automatically starting your engine periodically just to keep the engine lubricated and in good working order.
    • Longer brake life since you'll using regenerative braking...which puts braking energy back in your battery - an impossible feat in a gasoline powered car.
    • Very quiet operation...even when you put the petal to the metal - it's the quietest EV I've been in. 
    • Half Price fuel.  How about $2.10 for 40 miles of fuel vs. $4.36?  Assumes $0.13 kW/h, 28 MPG, and $3/Gal.
    • Smart Phone Control.  Check your available range...and chill down/warm up your car before you get in it...all from your smart phone!
  • It's quick/ least from 0-30 mph (which was all we could safely do in the parking lot).
  • Nice and clear dash/instruments.  The LCD display in the dash was clearly labeled and easy to control what you were looking at.  The LCD display in the center console was also easily understood and it was a touch screen.  The "buttons" on the central console were touch sensitive...which looks cool, but isn't something you can easily operate without looking at your finger.
All this said, I'm seriously considering getting a GM Volt.  Too bad Orlando is not on Volt's early adopter city list.

Here's what it's like inside...Trent takes us through the Volt's power up sequence, tells us all about the instrument panel, and narrates our drive. Nicely done.