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Engineers Develop Electric Car Battery That Can Heat Itself During Winter (popularmechanics.com)
Engineers at Penn State have created a battery that can self-heat, allowing for rapid charging regardless of the outside cold. The battery can reportedly provide a 15-minute rapid charge at all temperatures, even when the cold is as low as minus 45 degrees Fahrenheit. Popular Mechanics reports: Batteries have both positive and negative terminals. The scientists placed thin nickel foil with one end attached to the negative terminal and the other end creating a third terminal. When a temperature sensor attached to a battery detects that the battery is below room temperature, it then sends electrons flowing through the nickel foil. This heats the battery up until it's above room temperature again. When the sensor detects that the battery is above room temperature, that's the sign that charging that can begin again. Electric current flows into the battery, rapidly charging in a more efficient state. After 4,500 cycles of testing, the new battery only showed a 20 percent capacity loss, which could provide approximately 280,000 miles of driving and a lifetime of 12.5 years. This is compared to a conventional battery that "showed a 20 percent capacity loss after only 50 charges," reports Popular Mechanics. Penn State released a press statement with more details.
essentially a resistance heater in an electricity storage device.. for when the natural heat generated from charging isn't 'enough' to keep a suitable temperature?
wow. it took 'til 2018 to come up with that?
next you're gonna tell me they got a cooler for batteries for use in hot climates.....
No, sounds more like an integral heating coil that gets the charging current until proper temp is reached, at which point the current is switched to the battery itself. Simple and elegant as it can be all built into the battery, if you are into that sort of thing.
A group of Tesla owners on the Dutch-Belgium Tesla Forum are gathering data from over 350 Tesla vehicles across the world and frequently updating it in a public Google file. We have previously reported on the data, but they have since added many more vehicles and those vehicles have been driving a lot more – completing more battery cycles. The data clearly shows that for the first 50,000 miles (100,000 km), most Tesla battery packs will lose about 5% of their capacity, but after the 50,000-mile mark, the capacity levels off and it looks like it could be difficult to make a pack degrade by another 5%.
https://electrek.co/2018/04/14/tesla-battery-degradation-data/
The trend line currently suggests that the average battery pack could cycle through over 300,000 km (186,000) before coming close to 90% capacity.
If they say it can go 4500 cycles with a 20% degradation, then assuming a linear drop, a total distance of 280,000 miles implies...
280000/4500/0.9 -> 70 miles of range.
That's a compliance car. Even the Leaf is over 100 miles now, and most are over 200.
This sounds like it may be a nice solution for heating the battery during charging, but you also need to both heat and cool batteries during driving to keep them in the optimal temperature range. Can this also be used while also drawing power to drive the vehicle? It sounds like it only works with external power.
So if you assume that the battery will have external heating and cooling anyway, the elegance of the solution is lost, and now it's back to the question of whether this method of heating the battery is more efficient than using a traditional heating system.
EVs work fine in the cold, but it does reduce their range. A friend of mine used the same cells that Tesla uses to power a light for his dog sled in the Iditarod, and it worked flawlessly at 40 below.
Some cars do worse in the winter than others. My Tesla may lose a third of its range in extreme cold while my Leaf loses more than half. Whether this makes a particular EV impractical for you depends on the car and your needs.
I take issue with your "Not useful in Florida" title.
Sure, in Florida (at normal temperatures) the battery/controller would go straight to charging (and the normal cooling fans or whatever would kick in once it got hot enough). So it would work just fine, though it wouldn't use the "heat me up first" feature.
Until some winter when you drive up to Michigan, Quebeck, Alaska, or the nearest ski mountain or place where your kids can make snowballs, park it overnight at a motel or resort (because all the charging stations are full), then charge it in the morning while you eat breakfast. Oops! THEN you'll want the feature to be installed.
(It's really low weight, so hauling around a extra power transistor and some nickel foil heating elements doesn't cut into your mileage.)
So even if you don't actually use it in Florida it's still useful there - to the dealer selling you the car. B-)
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Yeah, it never gets that cold in Florida. That's why they never had problems with shuttle launches, and orange growers never panic about freezing.
I'll agree that it's rare to drop below freezing, but it does happen.
Also, it's not clear to me that the optimal charging temperature is anything above freezing. That's not a magic temperature when dealing with battery chemistry. I know my Tesla starts to have reduced regenerative braking below 45 or so until the pack warms up. For high speed charging, they'll probably want to heat to 45 or 50 for best results.
Interesting, but would it run Linux?
I thought Samsung invented those....
OR park it for 12.5 years on a trickle charger
You don't trickle charge a lithium chemistry battery. This is the #1 cause of lithium battery fires and explosions. To store them for long periods of disuse, you have to charge them to a storage charge (typically 50%) at which point they are good for about 2-3 years of storage. After that, they need to be restored to their storage charge again. Storing Lithium batteries at full charge accelerates internal corrosion (anode gets oxidized iirc), and will reduce the total lifespan of the battery by half or more.
Properly cared for, a lithium chemistry battery will still have 75% of its total capacity after 15 years and 1000 complete charge discharge cycles (or 5000 20% charge cycles) This means keeping them within their proper operating temperature and not charging / discharging them when they are too cold or too hot.
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The Model 3 doesn't even have a dedicated heater element: it uses waste heat from the motor to heat the battery and has some way to use the motor for heating even when not moving.
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My MacBook Pro is now 7 years old, is used daily and still has 84% of its original capacity so you must be right. That is good news for me because I hope it will male the 15 years, considering the abysmal rubbish Apple has on the market now.
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... fuel cells. The batteries are a stop gap. We need air breathing fuel cells to compete with hydrocarbon internal combustion engines.
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