Ford's confidence in lithium-ion is based on so-called Key Life Tests. The tests predict that the working capacity (y-axis) of lithium-ion batteries (green line) will be greater over a high-mileage lifetime (x-axis) than that of nickel-metal hydride (yellow line). Past field data for nickel-metal hydride (blue dots) has shown that the testing results are conservative -- that is, batteries generally do better in the field than they do on tests. (Source: Ford Motor Co.)
Cap'n, this is an interesting test methodology. I understand the desire to take out the dead time in operation of a vehicle. That makes sense. I wonder if there is some effect associated with that time though. If their results with nickel-metal hydride show that real world results are better than their tests that might indicate that the time spent resting is beneficial, at least for that chemistry. It will be interesting to see what the results are for these new batteries.
No offence to FORD, but they seem silly for tested NiMH against Lithium-ion. That was already established nearly a decade ago with laptops and cell phones. Perhaps they should have tested Lithium battery types instead. Like Li-poly or Li-air.
Also, the Toyota Prius did the research for them already. Lithium-ion has been standard for some time.
The use profile of a car battery is different than that of a laptop battery. It's less predictable and the environment is more harsh. Lithium-ion EV batteries are also massive and in many cases must be liquid cooled. Finally, there's the warranty issue: Automakers need to get a good handle on useful life, especially with today's EV batteries costing $600, $700 or even $800 per kWh. Remember the dead Tesla battery of 2012? The owner ultimately received a replacement quote of $40,000.
I hope that Ford does a better job of designing the battery electronics so they don't run into the dead battery pack issue like Tesla did. With Li-Ion packs the electronics will prevent the batteries from discharging to a voltage low enough to cause cell damage. They could put in a charge alarm or something simple when the battery pack gets close to this protect mode. Normally the pack will be charged from the engine (If a hybrid) but if the vehicle sits in storage for a long period of time this protect mode could cause more dead battery packs and a very disappointed customer. This is even more important in a full electric vehicle.
Yes, we'll find out after a few years in Ford's accelerated testing results were accurate, Naperlou. I realize that accelerated test is a fact of engineering life, but I have to admit that I as a consumer am always a little bit leery of it.
I agree with naperlou, the testing metholdology used by Ford is an interesting one. I guess there is no foolproof way to know for sure the effect the dead time has on the battery, but it seems like they did their homework. As in most cases with technology, it's usually time that is the best test to see how long it lasts and how durable it is.
Choosing Li-ion instead of NiMH may make sense for durability, but recycling may be a problem. Li-ion batteries typically don't yield much return when recycled, which requires someone to foot the bill. Recycling NiMH, on the other hand, can actually pay for itself. A typical Li-ion battery has less value when recycled than a lead-acid battery. As low as one third the value in some cases. For now, I believe only one company recycles large Li-ion batteries (Toxco), which is another concern. If the value of the recovered materials decreases over time, as predicted, it may become too unprofitable to recycle Li-ion batteries, which will create a disposal problem. NiMH seems like a more responsible choice. I understand that Ford must compete with other manufacturers who have already chosen Li-ion, so time will tell if consumers care enough about recycling to have an effect.
Ford choosing Lions is going to be a tough learning for them.. if I read the news right.
It's not the chemistry alone that makes it hard to make good and reliable systems. They should actually know what they are doing. :D
If they go and compare undersized Ni-MH hybrid pack to undersized Lion hybrid pack.... what's the catch here ?
Lions suffer from heat. Cycles will not be an issue at all. Ni-MH too dies when heated (forced bad designs like in EV-1). Undersizing the pack is good way to kill cells.
Accelerated detoriation is different. There are already a lot of research done this way to determine the wearing effects on cells. But it's only part of the equation.
Having Lion EV's on roads +10 years will tell them what is actually going on. If they do not have the experience and knowledge we can already say we will not see and considerable fleet on the roads in next 5-6 years. But they have to start from somewhere. Good to know they are trying to catch up.
Instead of making all the mistakes them selves they could buy the knowledge and experiences form companies who have had Lion EVs on roads +10 years.
What it comes to recycling only copper and cobalt are recycled from Lions. With Iron phosphates the recovery percentage can be extremely good. As the only dying component is the electrolyte.
What is somewhat troubling to me is that we've been hearing for years that replacement costs for NiMH batteries would come down, drastically, but is that statement accurate if that type of battery is obsolete?
We can buy 12V lead acid batteries, anywhere because they are still being used. However, if cost is based upon high production numbers, what happens when those numbers drop, years after a "better" type of battery is invented/tested/approved?
Not to go overboard in the use of industry jargon, but the technical description of that scenario is that "the customer is screwed."
On the plus side, aftermarket companies will in all likelihood jump in and offer conversion packages to enable owners to replace their old battery packs with the better technology. It's like converting an old pre-'80s car with a breaker-points ignition system to capacitive discharge (electronic) ignition.
I fear resources needed to create the Li-on batteries will start to become scarce, as more and more devices use them. Start manufacturing 700 pound versions of them will only hasten the demise. I would like to see Ford and Toyota look into alternative battery types, or even supercapacitors. I think supercaps will end up powering our devices in the near future, not sure about cars though. Caps can charge fully in a few minutes as opposed to hours.
The latest Mazda 6 uses a supercapacitor system, called i-ELOOP.
"When a car equipped with i-ELOOP is decelerating, a variable-voltage alternator (12 to 25 volts) pumps electricity into an electric double-layer capacitor (also known as a supercapacitor). When the car comes to a stop, Mazda's engine stop-start system—branded i-stop—takes over and shuts the engine off. At this point, all auxiliary vehicle functions (radio, HVAC, headlights, etc.,) are powered by the supercapacitor; its 25-volt output is stepped down to 12 volts by a DC/DC converter. There are times that the supercapacitor will recharge the 12-volt battery, too."
My bet is that the Ford engineers know more than they are telling. In the past few years I have observed that company to be doing a whole lot of really intense research in a variety of areas. So without giving away any of their secrets, I can offer that they do know what they are doing, but you will not get them to explain it. The rest of their secrets will need to come from their internal publicity group, I said all that I can disclose.
It's amazing no one bother to mention the small fact that Chevron who owns the NiMH patents won't let anyone build them over 10amphr and they do not play well together in parallel so no one can build EV's with them.
So in reality Ford, others if they want any kind of range have to go to Lithium batts. Now add Lithium actaully costs less than NiMh batts do mow plus NiMH uses Rare earth's that China is restricting exports on puts the nail in the coffin for them.
But the Chevron NiMH patent runs out soon but won't matter as Lithium has so surpassed them in every way from capacity, weight, impulse power and range.
And to the poster who thought Li materials are rare and short supply is completely wrong as cars already use the same materials except possibly Lithium which is not expensive or rare, in fact quite abundant.
Good point, Jerry. Definitely worth mentioning. It should also be noted, however, that Ford is using lithium-ion across the board, including in the second-gen Fusion hybrid and the C-Max Energi hybrid -- both of which use smaller batteries that would be unaffected by the Chevron 10Ah patent encumbrance. Ford told us they chose lithium-ion because it's "smaller, lighter weight and (has) better re-charging capability." And (this is what the article was all about) their testing capabilities gave Ford engineers confidence that lithium-ion would be more durable than NiMH.
I agree with Ford NiMH never was that good a battery and Lithiums have left it in the dustbin of history mostly because of it's more costly material and the fact that they need 3x's the cells because they are only 1.2vdc/cell.
On the post above supercaps won't ever be viable as they cost way, way too much for the pitiful capacity they have. Just do the numbers on them and it quickly become painfully clear.
Charles, do you happen to know if these batteries are standard in any way or are they built specifically for Ford? I know that they are suppose to last for pretty much the life of the car - at least the first owner, but it would interesting to see what happens after that.
Charles--very informative. I don't know that much about batteries but, is "working performance" (y-axis) the same as cold-cranking amps? I am assuming that's the case. If so, I can see how HALT (highly accelerated Life Testing) under hot and cold conditions, could bring about the conclusions you mention. I do have some experience with running components using powertrain dynamometers and the results for the equipment we tested were basically the same as actual "road tests". Again, very good update.
Tesla Motorsí $35,000, 200-mile electric car may not revolutionize the auto industry by itself, but it could serve as a starting point for a long, steady climb to a day when half of the worldís vehicles will be plug-ins.
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