Questions about electric vehicles answered


John D. asks:

“I own a Toyota Prius and love the fuel economy but the high-voltage battery required replacement is at about 150,000 miles. While I would consider a totally electric car, I have several concerns that I hope you can address:

1. Do I have to plug it in to an electric outlet every day? I really don’t want to have to do this.

2. Does the large battery reduce the space inside the car for passengers and trunk space?

3. How often does the high voltage battery need to be replaced and what would that cost?

4. Will an electric car cost me more in electricity than it will cost me to purchase gasoline for a conventional car? Thanks.”


Thanks for writing and sorry you had to replace the high-voltage battery pack in your Prius. I have known of many hybrid electric vehicles still going strong after 200,000 miles. If the car is used regularly and driven more than short trips every day, the high-voltage battery should last the life of the vehicle.

1. Do you have to plug in electric car every day? The short answer is no. For a typical electric vehicle (EV) that has a range of 200 miles or more, it needs to be plugged into a 220-volt outlet whenever the vehicle indicates that it needs to be charged similar to the fuel gauge in a conventional vehicle. For me that would mean charging overnight once a week.

2. The high-voltage battery is actually many hundreds of smaller battery cells that are underneath the vehicle. As result, the interior is open and often does not include a center “hump” resulting in a very roomy interior. Often there is a storage front trunk (frunk) where the engine would be located in a conventional vehicle.

3. The high-voltage battery should last the life of the vehicle. The batteries used today are cooled and heated using a separate cooling system that keeps the battery at an optimum temperature. It is this heating of cold batteries that reduces the range of an electric vehicle in winter months. Batteries work best at the same temperature that humans like (68 to 78 degrees).

4. No. Charging an electric car is a lot less costly compared to purchasing gasoline. For example, I calculated that it will cost me about $10 to charge my future electric vehicle that has a 250-mile range. That is at least half of the cost of gasoline to travel over 200 miles.

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