The reason from the article: “The development team selected lead-carbon batteries over lithium-ion equivalents as they require no active cooling, are more easily recyclable at the end of the vehicle’s life, and can function much more efficiently in sub-zero temperatures.”
Is this line actually true: "An often-overlooked feature of most Li-ion cells is that they cannot and must not be charged below 0°C, and have poor output current below 0°C."
Yes, virtually all batteries perform poorly at low temperatures. IIRC, the Tesla can actually heat its batteries to increase performance.
Most consumer-grade lithium ion batteries have a charging window between 0-45C, totally unacceptable for a car. 0-60C is more common for automotive batteries, but still isn't that large of a window.
Here's a diagram of the Tesla Model S's heat/cooling system. It's taken from a leaked picture of the engineering tools built into the infotainment system, which is a scary concept once you think about it:
The car needs a substantial amount of both active heating and cooling in order to enable the batteries to both charge at all below 0C and to charge and discharge extremely rapidly when attached to a Supercharger or under heavy acceleration.
Lead cells have worse cold-temperature performance than lithium; at least, all cells that EV conversions have used (golf cart/AGM/VRLA versus LiFePO4/LiCo).
Please provide a source on this, as this is directly opposite to what the article states, and dis-proven by millions of cars starting in freezing weather.
And the most relevant paragraph:
The performance of all battery chemistries drops drastically at low temperatures. At –20°C (–4°F) most nickel-, lead- and lithium-based batteries stop functioning. Although NiCd can go down to –40°C (-40°F), the permissible discharge is only 0.2C (5-hour rate). Specially built Li- ion brings the operating temperature down to –40°C, but only on discharge and at a reduced discharge. With lead acid we have the danger of the electrolyte freezing, which can crack the enclosure. Lead acid freezes more easily with a low charge when the specific gravity of the electrolyte is more like water.
> dis-proven by millions of cars starting in freezing weather
Car batteries are lead acid, not lead carbon. I'm not familiar with the technology, but I wouldn't assume the same performance for different chemistry.
Power Japan Plus also announced a new type of battery which is claimed to be suitable for cars, charges 20x faster than LiIon, has comparable energy density, ~ 3000 charge - discharge cycles, and will be produced this year in the standard 18650 format (but only for special applications like medical & satellites for now).
I couldn't find any capacity / discharge curves though.
This is a something of an indirect source, because I can't find the primary source for Axion's PbC cycle capability. But the PbC is far better than Power Japan Plus's.
"PbC lead/carbon chemistry creates a much longer lifespan (3 to 4 times), much greater charge acceptance in partial state of charge applications (10 to 20 times more depending on the "state" of the battery)."
Thus, Axion's PbC could have 8k cycles of complete charge/discharge, and orders of magnitude greater for partial discharges (which is how it would actually be used).
I have read it's over 100k cycles but I need to find the source.
"Our test protocol requires a complete charge-discharge cycle every 7 hours to a 100% depth of discharge. During testing, our laboratory prototypes have withstood more than 2,500 cycles before failure. In comparison, most lead-acid batteries designed for deep discharge applications can only survive 400 to 600 cycles under these operating conditions."
The interesting part about their batteries isn't the lifespan, it's the lifespan under 100% depth of discharge. You can easily get around 2k cycles out of a flooded cell lead-acid battery, but you can only go down to 60% discharge and you must carefully monitor the battery chemistry to get prolonged lifespan. Along with it's high current capacity, this would make it an interesting battery for renewable energy storage more than anything else.
It's too bad they don't have a solid datasheet for their product yet. I'd like to see their figures for internal resistance, self discharge and performance over typical operating temperature ranges. Until we get to see this data, it's hard to say if this will be a profitable product.
I have been following the development of lead-carbon batteries, and invested in Axion Power (AXPW). The primary advantage of lead-carbon batteries is that they can have orders of magnitude greater charge/discharge cycles than normal lead acid batteries. A normal lead acid battery eventually sulfates and will no longer accept charge - causing you to have to switch your car battery.
What the PbC does is have a carbon electrode on the negative plate, which prevents most of the sulfation problems. The positive plate experiences much less.
This is exciting because hybrid vehicles and other power applications demand many more cycles than traditional ICE auto. Previously this niche was only available to expensive and explosive Li-ion batteries. Now cheaper and safer lead-carbon batteries could be used (though they contain less energy).
Axion Power is a development stage company that holds the patent for a pure negative electrode PbC. Other competitor batteries pale by an order of magnitude to the number of cycles it can take.
It currently has the train company Norfolk Southern developing an all-electric train using Axion's batteries.
The reason the stock price is at 16 cents right now is because Axion has spent a decade developing the technology and is only beginning to see revenue. It has to raise money to continue operations. But the time is close.
A risky but potential very rewarding investment. Each potential market for their battery number in the billions.
Just curious, does this post fall afoul of SEC guidelines re: microcap stocks, or is it OK because all of the information is technically public? Not trying to be critical here (though based on the form of my question, I suppose I am), just curious.
I am not an expert, so take my opinion with a grain of salt. I think this falls into a bit of a gray area. One comment on a technical forum in response to an article where Axion Power was explicitly mentioned is probably OK. If the GP had a pattern of posting comments like this in many places, particularly investment forums, and under different usernames, it would be illegal market manipulation. Moreso, if that person was found to have bought, posted the comments, and then sold shortly after the market had gone up.
If the OP works for the company or is a stock promoter it might break some rules. Talking about your own investments (even hyping them) is not against any rules. The Internet is awash in stock forums.
There are other curious side effects, like a battery that is more or less sulfate proof would be nearly a permanent part of the car, rather then expendable "replace every could years".
On the good side, hey its cheaper maintenance, long term. On the bad side this could encourage massive vendor lockin, such that a conventional ford f150 with a custom f150-only battery that "should" last for the life of the truck could charge nearly anything they want for it...
I was on a team that built a lead acid hybrid race car in college. I seem to recall the batteries were by far the heaviest component of the car; at ~40lb a piece, they were more than half the gross vehicle weight (pilot and ethanol included).
Assuming Pb-C is roughly comparable to Pb-Acid in mass density (since most of the weight is presumably in the Pb), then you'd need ~twice as much to match it in energy density.
I'm wondering how massive the battery packs will end up being on such a vehicle.
>The reason lithium is used for electric cars is energy density. This is not a problem for hybrids.
I don't understand what leads you to conclude this.
The average US car is 4,000 lbs and has one battery. Your race car is not comparable.
You are correct about the energy density, but the battery is used for regen breaking, engine start/stop, hotel loads, and in the case of Kia an electric supercharger. Essentially it provides smooth-over power, but the bulk will still come from gasoline.
Lithium is used in electric cars where they are the primary energy source. Lead carbon is only appropriate in micro to mild hybrids.
None of those exploded. If you claim exploded, prove it!
Energy density is still useful for hybrids, especially PHEV. Earlier Prii use a very small lead-acid as 12V battery, but have a very large and heavy NiMH as the main pack. Doubling that weight is not a useful thing.
Telsa battery costs $20k because it goes >200 miles. What cost and weight would these batteries have in that same circumstance? (oh, it doesn't matter because they're only useful for hybrids, so why bring up Tesla?)
Most Priuses still use NiMH (all except the plugin one). In mine, it's around 120lbs, out of about 3200lbs total vehicle weight. Doubling the weight of the battery wouldn't make that much of a difference.
Plugin hybrids and pure electrics need much larger batteries, so it certainly matters there, but for plain hybrids it's not such a big deal.
Though there's certainly a difference, I'm not sure it's all that important here. A fire followed by a mild explosion isn't necessarily that much more dangerous or harmful than a fast fire. You don't really want either.
My (not very scientific) findings while working on nautical equipment for stuff like barges and buoys are that the more weight-efficient a battery is, the less environmentally tough it is. We use SLA batteries wherever we can simply because they are likely to last for years where they're deployed.
15% better fuel economy is certainly noticeable even if it's not huge. Lots of car buyers prioritize fuel economy these days. Not every improvement has to be an order of magnitude.
As electric cars become more popular, expect taxes on them to go up as well. Germany recently scrapped fuel tax breaks for biofuel. In the long run, it's unlikely for tax breaks to be maintained on popular items of consumption.
Rational tax policy would levy taxes in proportion to the externalities produced by any given activity. Cars which emit air pollution generally produce more external costs than those which don't, so it would be reasonable to expect taxes on them to remain higher forever.
How about a full-electric car - 100% co2 reduction. Why make this car, with its dual power systems. When on gas, its lugging the electrics around - has to hurt gas mileage. The electrics have to lug the gas engine around. All for 15% reduction, when 100% reduction was possible. Why do it? Because its some profit point for the manufacturer.
The cost of the PbC once it scales up to auto production level would be about 250 dollars. That is in range of a high end lead acid battery.
Compare the cost of a NiMH battery (3k or so) or a Li-ion battery (10-20k). The savings for a simple change far outclasses what heavy hybrids or full electrics can do dollar for dollar.
The numbers you are comparing are not even close to the same energy capacity.
LiFePO4 can be bought for ~$.33/Wh
A flooded golf cart battery is the very cheapest per Wh, and they are about $.10/Wh assuming 100% capacity (which you can actually only use 50-80% of, boosting cost to $.13-.22/Wh).
The whole point of a "mild hybrid" such as what's discussed in the article is that you can get some of the benefits of a hybrid with a much smaller battery and motor.
You can spend a bunch of money on a full hybrid system and get large increases in fuel economy, or you can spend a small amount of money on a "mild hybrid" system and get a small increase in fuel economy. What he's saying is that, for the small amount of money involved, a 15% gain is pretty decent.
Is this line actually true: "An often-overlooked feature of most Li-ion cells is that they cannot and must not be charged below 0°C, and have poor output current below 0°C."