Should Chevy Bolt Buyers Fear Losing ‘As Much as 40 Percent’ Battery Capacity?

A story making the rounds has it that the Chevy Bolt EV’s owner’s manual cautions 10-40-percent battery capacity loss is possible, but should this warn away prospective buyers?

In response to our query, Chevrolet has suggested not necessarily, and such warnings are not beyond the pale of other EVs’ disclaimers, but the prospect of 143 miles remaining from a “238” mile EV could sound alarming.

That is a worst-case scenario Chevrolet on page 322 of the owner’s manual says could happen within the 8 year/100,000 mile warranty. In other words, 40-percent loss could mean 143 miles left for the $37,495-before-incentives car. Note also the warranty covers just 12,500 miles per year, so drivers who do over that stand to be out of warranty before the 8 year period is over.

And, the worried might note, to be left with as little as 143 miles range does not sound good at all, but as the owner’s manual states, it is a possibility:

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.”


But while this may make for a good stir-the-pot story, and could incite knee-jerk responses, it is far from likely Bolt EV owners will see such degradation, and warnings of serious capacity loss are a normal industry practice.

As a forum poster observed, several other EVs have had warnings of up to 70 percent capacity retained and the Nissan Leaf allows for 9 out of 12 bars.


So, the Bolt’s as little as 60-percent capacity retained is a greater theoretical loss, but does that mean Chevrolet has less confidence in it?

According to Chevrolet Communications Representative Fred Ligouri, it would seem this is not the case.

“In an effort to provide complete transparency to our customers, it is true that under extreme circumstances it’s possible that someone could experience between a 10 percent to 40 percent reduction in range over the course of the 8-year/100,000 mile warranty period,” said Ligouri. “As we have seen with the more than 100,000 Volts on the road, our battery packs maintain their range and capacity very well over the life of the vehicle with minimal and varying levels of degradation. Like Volt, the 2017 model year Bolt EV offers one of the most competitive battery warranty coverages in the industry.”

The LG Chem battery cells in the Volt are thus being held up as an indicator of what to expect in the Bolt.

To date the Volt – whose warranty allows as much as 30-percent capacity loss – has not seen any batteries replaced under this provision.

Further, General Motors has noted its LG cells are “pharmaceutical grade,” with a mere two problems per million cells produced.

On the extreme end of things, one Chevy Volt has been reported with north of 100,000 EV miles, and 300,000 road miles with undetectable degradation – though certainly others have not been as fortunate.

SEE ALSO: Erick Belmer’s Chevy Volt Traveled Its 100,000th All-Electric Mile Today

Further in the Bolt’s favor is the battery – as true of the Volt – is actively thermally managed, which includes liquid cooling to help protect against heat damage.

The Nissan Leaf’s battery by contrast, has no such hot-weather protection, and has seen more issues with capacity loss.

In any event, Ligouri’s statement fits also with those who’ve said the up-to-40-percent capacity warning is just covering liabilities.

Some capacity loss is however likely over the warranty period, and owners will have to determine whether they are OK with that.

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