On page 322 of the Chevy Bolt owners manual, Chevrolet says the Bolt battery may experience 10 percent to 40 percent battery capacity loss over 8 years. Even though that information was made public and discussed by both AutoBlog and Green Car Reports last year, the fact that deliveries of the car have begun seems to have ignited a new round of interest in the story. Here’s what the owner’s manual says:
“Like all batteries, the amount of energy that the high voltage “propulsion” battery can store will decrease with time and miles driven. Depending on use, the battery may degrade as little as 10% to as much as 40% of capacity over the warranty period. If there are questions pertaining to battery capacity, a dealer service technician could determine if the vehicle is within parameters.”
If you are considering purchasing a Chevy Bolt, should you be concerned? After all, we hear that replacing a battery can be an expensive proposition. Nobody wants to get stuck with a big repair bill and used EV prices will be adversely affected if buyers are worried their batteries are about to fail. Here’s some information designed to put your mind at ease.
First of all, the Chevy Volt is probably a good place to look for information about battery loss. According to Volt owner Erick Belmer, his 2012 Volt racked up 300,000 miles with virtually no battery degradation, according to a post he put on Facebook last March. Chevrolet is extremely happy with LG Chem, its battery partner. The average failure rate for individual cells in the Volt battery pack is a minuscule 2 for every 1 million cells in service.
Second of all, some electric car manufacturers don’t warranty their batteries against loss of capacity at all. Surprisingly, one of those is Tesla. Gary Exner of the Oregon Electric Vehicle Association compiled a list of EV manufacturers and their battery warranties, which he furnished to Electric Car Reports in December. Notice on his chart the Bolt EV battery warranty is listed at 60% capacity. Clearly, there is a discrepancy between Exner’s information and the Chevy Bolt owner’s manual. You should consult your local dealer for the latest information.
The life of an EV battery is affected by many things. It is generally believed that fully depleting a battery and then charging it to 100% on a regular basis has a negative effect on battery life. Many EV owners like to stop charging at about 80% capacity because they believe doing so will extend their battery life. Extreme cold and extreme heat have a negative effect on battery life. Liquid cooled batteries seem to be more durable than air cooled batteries. Stomping on the throttle all day every day seems like a good way to shorten battery life.
Warranties are complex things. In all likelihood, the legal beagles at GM had a hand in crafting that language on page 322, in order to protect the company from having to give a new battery to some clod who abuses a car on a regular basis. People who buy cars with internal combustion engines also risk catastrophic loss if the engine fails after the warranty expires — usually 36,000 to 60,000 miles. The price of a new engine is probably not all that different than the price of a new battery. If you aren’t worried about one, you shouldn’t be worried about the other.
GM could probably help themselves out, public relations wise, if they bumped up the protection on the Chevy Bolt battery. The cost of a few batteries down the road would be more than offset by the good will a stronger warranty would bring them. For now, the great Chevy Bolt battery controversy seems to be little more than a tempest in a teapot. If you want a Bolt, buy one. In the words of Bobby McFerrin, “Don’t worry. Be happy!”
Source: Green Car Reports Photo credit: Chevrolet