Volt Webchat: How to Maximize your EV Range
Photos by Joanne M. Tucker
The Chevrolet Volt at the L.A. Auto Show - 2011. Click here
for a full gallery of the event.
In a Chevrolet Volt webchat on Dec. 9, the energy integration engineer for General Motors Corp., Larry Laws, gave some insights on how to get the most from your electric vehicle (EV) range.
Larry Laws: Hi everyone and thanks to all of you for joining today. Looking forward to the chat. Let's get going!
Q: Below which temperature will the Volt start heating the battery?
Larry Laws: That will happen at zero degrees Celsius.
Q: My wife has a 2009 Malibu and she will drive the Volt because it's better in the snow. What makes the Volt drive better in the snow?
Larry Laws: It's actually the Volt tires that give the car good snow performance.
Q: Is there any overall energy advantage to running in Mountain Mode once the generator starts to charge the batteries so that you can run additional time later off the batteries? I noticed that the generator is really working in Mountain Mode and would assume it is using more gasoline during that time.
Larry Laws: In the energy equation, it's not better to charge the battery from the engine. It's more efficient (and better for the environment) to charge the battery off the wall. Mountain mode is used for high-load conditions.
Q: I have had my Volt for about a month. It's starting to get quite cold here in Minnesota (0 degrees this morning). I am wondering what will happen when we have a REALLY cold day, perhaps it never gets above 0 degrees, when my Volt is parked outside for maybe 8-10 hours. Will the battery be warm enough to start the car?
Larry Laws: The battery is designed to start the car at temperatures as low as -30 degrees Celsius. Below that, we recommend you keep the car plugged in.
Q: I use the OnStar warm-up function when my car is in the garage and plugged in on cold days. Because I mostly charge overnight I haven't opted for the 220v charger and use the 110 version that came with the vehicle. I've read that warming off the 110 charger will still result in the ICE coming on at times of battery depletion or extreme cold. Is that true?
Larry Laws: The 240-volt charger has more power and can preheat the cabin a little bit better, but the engine cycling is based on ambient temperature and coolant temperature and neither (240-volts or 120 volts) will prevent the engine from coming on when it is extremely cold.
Q: When one remotely starts the vehicle and it is plugged in, is it possible that the gas engine may turn on while the car heats up or does that only happen when the car is not plugged in?
Larry Laws: Yes, the engine can still turn on when the car is plugged in when it is extremely cold out to provide cabin heating. Plugging in or not plugging in doesn't change the behavior of the car in terms of the temperature in which the engine will come on.
Q: Does preheating the car off of 110 power deplete the battery at all?
Larry Laws: Yes, some energy will come from the battery, especially if it is very cold outside.
Q: Is the Volt better insulated against cabin temperature loss? When I turn the heater off in my regular car, I can feel the temp dropping immediately. I suspect pre-heating the Volt while plugged in will only feel good for a few minutes.
Larry Laws: The Volt will retain and cold the same as any other new car.
Q: Most of my driving is short distances and I haven't been using any climate controls hoping that I will conserve battery charge. Is this a good idea?
Larry Laws: Yes, not using climate control will help maximize your EV range. I say go for it as long as you're OK with the temperature in the car.
Q: After driving 5,500 miles in Volt now, I am noticing a huge drop-off in EV range starting in September. I used to be able to get up to at least 48 miles, but after September I can't break 38 no matter how hard I try. Just so you understand: I use zero heat (no heated seats, not even a fan speed at the lowest in non-A/C mode). Can the drop from 48 or more down to 38 or less be completely due to something else? Tire inflation only? Or something else? Yes, the temperature is down, but if I don't use any heat at all...
Larry Laws: That seems more than I would expect. Obviously, check your tire pressure, but that wouldn't account for that much EV range. My advice is to try turning off auto-defrost.
Q: I have been getting condensation on the inside of the windshield on a few cold days. If I don't use any other climate controls, what temp setting on the defrost should I use to conserve battery charge?
Larry Laws: The low setting would use the least amount of energy.
Q: Question about Cold an Hot during working hours. I have read a bit about maximizing the life of the battery. It appears that you will have some life loss if your car is sitting unplugged under 32F or above 90F. Is that correct?
Larry Laws: Those are the temperatures where we try to maintain the battery. The life equation is much more complicated than temperature alone, but generally, it's much colder and somewhat hotter than that.