GM talks up EV battery longevity tech
How it'll make Li-ion go further (and not explode)
'Leccy Tech With some of our media colleagues giving the distinct impression that the current cold snap is on a par with the one that stopped the Wehrmacht at the gates of Moscow in 1941, Green Fuels Forecast have had a timely chat with some senior General Motors staffers about battery lifespans and operating temperature issues.
Temperature is a big deal with it comes to 'leccy vehicles powered by lithium-ion batteries for the simple reason that below about -10°C their performance drops off rapidly – as indeed it does above 60°C too, but far more of us are likely to driving around in the former temperature than the latter.
Inside the Ampera
In due course, new generations of Li-ion battery electrolytes may overcome the problem, as indeed may new types of battery - one of the claims Altairnano makes for its NanoSafe battery is an operating temperature envelope of between -30°C and 249°C - but in the short term, battery management is the only way to go.
Answering questions specifically about the Chevrolet Volt/Opel Ampera in an interview with Green Fuels Forecast, Denise Grey, GM's Director of Hybrid Energy Storage Systems, and Bob Kruse, Executive Director of Hybrid Vehicle Engineering, recently shed some light on how GM's Great White Hope will cope various battery related demands.
Most interesting was the revelation that as it currently stands the Volt won't let you pull away under charged power if the temperature gets below -10°C. Instead, the 1.4l range-extender petrol engine will fire up and drive the generator until the system gets warm enough for the battery pack to reach its optimum operating temperature.
In an effort to prolong the life of the Volt's battery pack, Kruse explained, it won't charge to above 80 per cent of capacity, nor will it deplete to below 30 per cent. Allied to its liquid-cooling system, this should help prevent the heat build up that causes electrode cracking due to thermal stress and so enable GM to meet its ten-year/150,000-mile durability target.
Kruse also went on to say that the experience GM gained in battery management during the much heralded development and launch – and rather less heralded withdrawal – of the EV1 electric car has given them a useful competitive advantage.
Presumably, GM staffers who sweated and toiled on the EV1 have been able to hold their heads up high since GM CEO Rick Wagoner's 2006 admission that the worst decision he made was "axing the EV1 electric-car programme”.
GM's interest in battery management – rather than battery cell manufacture – has been underlined by the planned 31,000sq ft battery assembly and testing facility that it's due to build at its Warren, Michigan technical centre later this year as part of Wagoner's intention to make battery technology a “core competency” at GM.
Testing, testing, 1, 2, 3...
The Warren battery lab will offer free testing facilities to any battery manufacturer, though GM isn't being wholly altruistic in this – the quid pro quo is that GM gets access to all the performance and test results.
In related news, Grey also recently said that GM has been in contact with EEStor, the highly secretive Texas company which claims – but offers absolutely no proof – that it's close to developing an ultracapacitor-like energy storage unit that allegedly gives several times the energy density of lithium-ion batteries at a fraction of the cost and with a functionally infinite lifespan.
We'll believe that when we see it, drive something powered by it, or get an electric shock from it. ®
Why Electric Cars are slow coming to market
Email received from an American:
Why Electric Cars are Slow Coming To Market - You'll Never Guess!
If GM could build the EV1 to go up to 150 miles on a full charge 10 years ago, why can the Volt only go 40 miles on a full charge today? Excellent question. Surely, battery technology has advanced in the past 10 Years, right. Yes, but that's not the real problem. The battery pack powering the EV1 was NiMH (nickel metal hydride). The Volt will be powered by lithium ion batteries like the ones in laptops and cellphones.
So, yes, battery technology has advanced in the last 10 years, but the problem of reduced battery range goes beyond that. The "regression" in battery capability is intentional. Here's why:
In 1994 General Motors bought a controlling stake in ECD Ovonics. By doing so, GM gained control over the development and manufacturing of Ovonics large NiMH batteries. This move also provided GM with all the patents on the batteries. These NiMH batteries were used in the final examples of the EV1 in 1999, and reportedly worked flawlessly. Fast forward a couple of years to 2001, and a relatively unpublicized transaction took place. GM sold its share of ECD Ovonics (and the patents) to Texaco. Yep, the oil company. Six days later, Chevron completed its' purchase of Texaco. So now the battery technology that allowed the EV1 to run for 150 miles without a single drop of gasoline is in the hands of one of the largest oil companies in the world.
In 2003, Texaco Ovonics Battery Systems was renamed Cobasys, a 50/50 joint venture between Chevron and ECD Ovonics. Independently, Chevron owns a 20% stake in ECD Ovonics.
By now, you are probably guessing that an oil company with the patents to a very effective battery technology would never let that technology see the light of day. It could very well put them out of business.
To state that the technology was buried is not entirely true. But what Cobasys did is extensively limit the ability for any one to get their hands on NiMH batteries. Anyone found utilizing the NiMH battery technology that Cobasys had the patents on were sued and sued often, such as Panasonic. In essence, Cobasys controlled the market for NiMH batteries, and they were doing their best to make sure none of the batteries made it into any electric vehicle.
That brings us nearly full-circle to the current crop of electric vehicles, including the Volt. The Volt will run on costlier lithium ion batteries, which will drive up the cost of the Volt. GM could have used the cheaper and proven NiMH batteries, but alas, they sold the patents to Cobasys (Chevron). Do you think Chevron would allow the Volt to be produced with NiMH batteries, eliminating the need for a gasoline engine to supply power after 40 miles? Not a chance.
Cobasys is allowing their NiMH batteries to be used in the Chevy Malibu Hybrid, the Saturn Aura Hybrid, and the Saturn Vue Hybrid. But all of those vehicles are hybrids, so they still rely on gasoline. Not one
vehicle is utilizing Cobasys batteries as the sole source of power.
It gets better. The company chosen to supply the Lithium Ion batteries for the Volt is called A123Systems. Guess with whom they are partnered? Cobasys.
Great. So, to bring this all together the battery technology from 10 years ago that powered a car 150 miles, is now controlled by an oil company, and any new hybrid vehicle in production now relies on batteries from an oil company. Is it any wonder that we are 10 years down the road from the EV1, but have yet to see a true mass market electric vehicle? Not when the technology is owned by an oil company.
I guess we can only sit and wait until 2014 when the patents expire.
A familiar figure
"In an effort to prolong the life of the Volt's battery pack, Kruse explained, it won't charge to above 80 per cent of capacity, nor will it deplete to below 30 per cent."
And when did the Tesla Roadster - which uses the same battery technology - run out of steam on the Top Gear test track? Why, with 30% charged batteries, whined the makers.
BOFH turns his hands to traction batteries
"We'll believe that when we see it, drive something powered by it, or get an electric shock from it."