Published May 21, 2012
By Jeff Cobb
The Chevrolet Volt and Opel/Vauxhall Ampera represent a new kind of powertrain for General Motors which the company has covered with an 8-year/100,000 mile warranty, but what happens to that expensive battery should it cause issues, or after its usable service life?
We’ve heard critical speculators say Volt owners will be in for a new battery shortly after the 8 years, or 100,000 miles (160,000 km) – whichever comes first – thus wiping away the savings offered by potentially bypassing the gas pump due to its ability to operate as a medium-range electric vehicle.
In short, there’s no reason to suspect this worst-case scenario will be the case.
To begin with, the Volt/Ampera battery does not have a “die gene” imposing electrical rigor mortis on a vehicle left in the hands of a hapless owner as soon as GM’s warranty liability period is over.
It is true the battery loses its charge holding capacity, but there's reason to believe it's over-engineered. It is thermally managed with liquid cooling and heating, and GM built in a "buffer" zone in which its battery management system never fully charges or discharges the pack. In fact, only 10 kilowatt-hours out of a total 16 are ever used as a means to preserving its longevity.
But according to GM’s Manager, Electric Vehicle and Hybrid Communications, Kevin Kelly, what GM has fully disclosed already is it does not quite know all the potential scenarios that could play out for aging Volt and Ampera batteries – but “we’re working diligently on it every day” he said of potential re-use scenarios and related questions.
By definition, GM considers the 16-kilowtt-hour Volt/Ampera battery to be at the end of its usable life cycle when it has around 70-percent charge-holding capacity. When exactly that threshold is reached could vary widely depending on climate, and how the vehicle is used – but what it also means is the battery is not useless after its “usable life.”
Post Retirement
If someone buys a Volt or Ampera and intends to run it till the proverbial wheels fall off, he or she will be faced eventually with a decision about the aging battery.
The greatest likelihood is someone will simply notice a progressive diminishing of its all-electric range.
Newer Volt owners have reported range varying from around 25 miles in cold weather to just over 50 miles with gentle driving in perfect weather – batteries function best and "like" the same moderate weather humans do, and the Volt's battery thermal management helps keep it closer to its ideal zone.
As one potential scenario, if someone normally gets, say, 38 miles electric range on an average day, and the battery became 75-percent worn out, the car might get only 28.5 miles electric range compared to when brand new. So no doubt, owners will see usable electric range drop over the years.
If they go well-beyond the warranty period – like 10-12 years or longer and well over 100,000 miles – the battery at some point will have probably degraded below its nominal “70-percent” usable life, but it still should have usable life – just not as much.
The good news is it won’t be an expensive-to-replace dead brick as some critics have implied. The not-as-good news is, the Volt/Ampera owner will benefit less from electric-only driving, which was a primary reason for buying the car.
The standard 8-year warranty averages to 12,500 miles driving per year. If the Volt/Ampera driver travels farther per year, naturally, the warranty will be exhausted sooner. When ever the end of "usable life" comes, again, it won’t be a definite end, but more a tapering off.
Future Unknown
Exactly what the most sensible decision will be for a future degraded battery, say, in 2020 is anyone’s guess – including GM’s – but that is why the company is researching and developing several possibilities now.
Kelly says the company has test Volts with well in excess of 200,000 miles still operating within spec which means the liquid-heated and cooled battery and related systems are engineered to at least go the distance in all climates.
But since this is a new kind of car in a nascent industry in which energy storage technology is developing – and battery prices are dropping on existing lithium-ion chemistries – Kelly says he cannot say what might be the best option at the end of the warranty period.
In as far away as eight years from now, it could be an upgraded original equipment retrofit, or the standard battery, which at present is the only recommended replacement.
How much would it cost?
“We don’t know that. We just don’t know that. Battery chemistries and battery technology is advancing at a rapid pace,” Kelly said. “We’re seeing the cost curve come down pretty significantly and we’re looking into other chemistries and other materials. We’re looking at ways to improve the value equation.”
If this kind of uncertainty alarms you, perhaps a Volt is not right for you, but that is not a conclusion GM would suggest, as it has a do-what-it-takes policy in place to help soften the potential edges of adapting to its new technology.
Since the Volt’s launch, GM has offered white glove treatment for its early adopters better than Cadillac service. Consumer Reports rated the Volt as number one in owner satisfaction at 93 percent, currently placing it above all cars sold today.
During the recent publicity crisis in which the federal government was investigating the Volt’s battery, GM actually offered to buy back Volts from customers who were concerned for their safety; this move was considered above the call of duty, and Kelly said the company will continue to offer high levels of assurance all the way through the lifecycle of the Volt or Ampera in years to come.
That’s not saying GM is opening itself up to frivolous claims, but merely that it has policies and procedures in place to prevent Volt owners from coming out feeling like losers for having taken a chance on the car.
Should a battery need repair or replacement within warranty, by the way, Kelly said the company just contracted with Midtronics for tool that can "de-power" and service the Volt/Ampera battery.
The large T-shaped lithium-ion battery pack is comprised of LG Chem cells constructed in nine modules of varying capacities. Dealers authorized to work on the Volt/Ampera receive training on diagnosing its battery. In a warranty situation, dealers may replace modules or whole battery assemblies.
The policy is that should an entire battery be replaced, owners will get a new replacement battery. On the other hand if it is a repair scenario, the dealer is authorized to restore the battery to pro-rated performance levels on par with where the battery should have been at that point in its life. So, for example, if it is a four-year-old battery, a repair does not restore to new-spec charge holding capacity, but to a level on the anticipated wear curve for a normal four-year-old battery – exactly how much usable life is expected year after year of use is info that GM keeps confidential.
Unknown is whether aftermarketers would be in business to offer replacements.
Unknown is what value a used battery would have if an owner wanted to replace it, or how an owner would be credited or paid for a used battery that still has, say, 69-percent or less usable life in it. Kelly was unwilling to say what he thinks a used Volt/Ampera battery might be worth after so many years, but that it will have value is at least certain.
Of course all this becomes moot if someone leases the car, and simply turns it back in. Or, if longer-range, higher performance, electrified vehicles come down the pike as GM says they will, people may not even want to hold onto their old Volts.
So, as you might expect, also unknown is the used car market for first generation Volts a half decade or longer from now. Out of the gate, leasing companies have erred on the safe side, and projected lower values than might be expected for comparably priced gasoline cars.
Possibilties
While Volt/Ampera owners may opt in the future to replace their battery because its vehicle propulsion value is below acceptable, again, the used battery is not scrap, and GM is looking into ways to intelligently re-purpose the Volt/Ampera battery.
One possible way is being worked on in collaboration with ABB Group. It and GM engineers are putting used Volt batteries back to work – with what capacity they have remaining – into energy storage devices for use by subdivisions, industrial parks, businesses or the like.
“GM’s battery leadership position doesn’t stop at the road – it extends throughout the life of the battery, including ways we can benefit society and the environment,” said Micky Bly, GM executive director – Global Electrical Systems, Electrification and Infotainment. "As we grow our battery systems expertise, we need to assure we’re optimizing the development of our battery systems with secondary use in mind from the start.
“Partnerships with organizations such as ABB provide real-world applications that prove what we’re doing is real, not fiction,” Bly said.
Kelly said later this year, GM and ABB will test a pilot project of re-purposed Volt batteries. This would involve reconfiguring the used modules, perhaps into squared shapes for mounting in a box sited at a facility, not merely re-using the entire Volt’s T-shaped pack which is shaped that way to fit the car.
Beyond this, Kelly said the company is looking at a number of different scenarios.
Again, like its customers, GM has not traveled this path before. The upside is the Volt is showing a major payback unlike conventional cars, so the belief by those who buy them is it will all pan out.
In the meantime, Kelly reiterated GM intends to stand by its owners all the way through.
“We want them to be happy,” he said, as GM continues to develop its technology – and wants repeat business.
Given the way GM has treated its Volt customers to date, we have seen no reason to suspect its stated position is anything but true.
