2014 Volt - REduced EV range

A fully charged Volt battery holds a fairly consistent amount of power each time you recharge it, represented by 10 green bars on the display screen.

How far you personally can drive on those 10 bars of power depends in many ways on the same factors that determine how far you can drive on a full tank of gas, i.e., your driving habits, the weather and terrain, and the condition of the car (e.g., new/old tires, etc.).

Electric cars, however, also draw power from the battery for the accessories (heat and air conditioning may use significant amounts), leaving less as fuel for the electric traction motor. Turning up the heat or a/c may reduce the ev driving range.

Bad weather can require the car to use more power to move the same distance (takes more power to move through falling rain and cold, dense air and to splash through puddles on wet pavement, etc.), and such conditions often are coupled with increasing use of heat and window defrosting. Most Volt drivers experience annual range cycles, increasing during warmer seasons, decreasing in the colder seasons.

The full charge ev range display is the computer’s estimate, based on the data it has recorded of your past driving achievements, of how far those 10 bars of power will enable you to drive if you drive as you normally do. If the weather or your driving habits change, or if someone else drives the car, the car’s electric mileage for that particular full charge may improve or deteriorate.

villib said:

Thanks for all you replies, I really like this forum. My concern is that I charge the car inside in ~68°F. When it's fully charged, 10 bars the range shows around 26 miles.
I understand it will degrade based on temperature and weather as well.

Click to expand...

The temperature when you’re driving the car affects the full charge estimated range far more than the temperature surrounding the car when you are charging it. A full charge range of 26 miles means the computer estimates you’ll go ~2.6 miles for each green bar of power you use. See if you can drive more efficiently, use less heat, etc. If better driving habits can increase that to ~3+ miles per green bar, the full charge estimate will also increase. Press the leaf button and observe the usage display in the center stack. How far can you drive on 1 kWh of power used? See if you can get it up to 3 miles/kWh or more... Increasing ranges, of course, usually return in the spring...

There’s nothing really mysterious about range estimates... multiply the amount of available fuel by some sort of mileage figure to get the range. But let’s also acknowledge that there is a difference between the "full charge" range estimate and the "on the fly" estimate you see once you unplug and start to drive down the road.

The full charge range estimate is based on historical data regarding your driving. The calculation is influenced more by recent driving history than by past events. If you reach home after driving for miles up steep hills with the heat blasting away, the impact that power demand had on the electric mileage during the final leg of your drive may indeed negatively influence the next day’s full charge range estimate. I suspect the overnight ambient temperature in the garage where the car is being recharged plays little part in the full charge range estimate. The computer analyzes the data, then uses an algorithm to calculate an average electric mileage figure appropriate for use for the next full charge. The full charge range estimate is nothing more than this number multiplied by the amount of available power in the fully charged battery.

You don’t have to drive far enough to deplete your battery to get your full charge estimate to increase, you can do it by getting great mileage when making those short trips. Better mileage multiplied by available power in the full charge = higher full charge ev range estimates.

Once you start driving, the range estimate is soon influenced by the driving conditions you are experiencing. The computer’s algorithm creates an "on the fly" estimate of the battery soc to determine the remaining amount of power, adjusts the full charge mileage estimate to reflect current conditions (speed, terrain, weather conditions, etc.), and then calculates the estimated remaining range. When the range goes up while driving downhill, for example, many people think downhill regen is "adding miles to the range," but it’s really not... most of that increase is because the car thinks you’re going to keep driving downhill, and downhill mileage is better than level terrain mileage, so the distance that can be driven using the available power increases. Once you hit level terrain again, the estimated range will quickly decrease as it adjusts itself back to level terrain mileage.