# Thomas Edison's car battery is back, and it's better than ever



## PhantomPholly (Aug 20, 2008)

This may have been reported before, but it looks promising. Key is that the theoretical chemistry may have an unlimited number of charge-discharge cycles.

*Thomas Edison's car battery is back, and it's better than everhttp://www.siteadvisor.com/sites/io...cale=en_us&ui=1&os_ver=6.1.1.0&ref=safesearch


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## Ziggythewiz (May 16, 2010)

You're right. It _has_ been reported before  I didn't see anything about unlimited cycling though.



sentraelectric said:


> nickel-iron battery fast charging
> 
> [URL]http://www.bbc.com/news/technology-18674240[/URL]





PhantomPholly said:


> Ah, well. Still, I think this nanowizardry is the way things are headed. When the breakthrough comes it will be some cleverly layered bunch of goo...


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## PhantomPholly (Aug 20, 2008)

Ziggythewiz said:


> You're right. It _has_ been reported before  I didn't see anything about unlimited cycling though.


The original Edison batteries effectively never wore out (if the chemicals degraded because the battery was not maintained, they could flush and refil with fresh electrolyte and they worked fine). This newer version with nano-stuff seems to suffer some degradation over time, but perhaps they will find a way to fix it.


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## Zappo (Sep 1, 2011)

PhantomPholly said:


> The original Edison batteries effectively never wore out (if the chemicals degraded because the battery was not maintained, they could flush and refil with fresh electrolyte and they worked fine). This newer version with nano-stuff seems to suffer some degradation over time, but perhaps they will find a way to fix it.


The article didn't mention one other problem with the original design Edison batteries. They weren't very efficient. From everything I've read, you only got out between 50% and 60% of the energy you put into the battery. I have some that were made in the 70s. They still work but I have never checked to see if the (lack of) efficiency claims were true though.


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## david85 (Nov 12, 2007)

The supplier I got my lithium battery from did show a nickel iron flooded prysmatic type (among a wide variety of other battery chemistries). Weight and efficiency concerns kept me from enquiring about them. I thought it was interesting to see a modern source was available.


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## PhantomPholly (Aug 20, 2008)

Zappo said:


> The article didn't mention one other problem with the original design Edison batteries. They weren't very efficient. From everything I've read, you only got out between 50% and 60% of the energy you put into the battery. I have some that were made in the 70s. They still work but I have never checked to see if the (lack of) efficiency claims were true though.


"Efficient" compared to what? If the electricity you use comes from a plant that is 3 times as efficient as burning the same fuel in your vehicle for propulsion, then a battery 50% efficient is better than fueling up with gasoline.

Nickle Iron batteries were in fact a tad inefficient. The biggest impact on efficiency seemed to be the rate of charge and discharge, and the second biggest was that they do tend to lose some charge over time. I've seen claims of up to 80% efficient if they were charged slowly and used shortly afterwards - the type of use you expect normally from EVs. 

Energy density wise, NiFe is better than lead acid but not better than NiMH. The bonus was you could run them flat dead and recharge them; the disadvantage was that they were not capable of high C discharge rates, they don't work well in the cold, and that high C rates (either charging or discharging) made them less efficient. The article's described approach essentially causes an explosion of surface area - and since chemical reactions vary proportionally to surface area, I suspect that that approach may mitigate the disadvantages quite a bit if they can overcome the declining capacity issues.


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## Zappo (Sep 1, 2011)

PhantomPholly said:


> "Efficient" compared to what? If the electricity you use comes from a plant that is 3 times as efficient as burning the same fuel in your vehicle for propulsion, then a battery 50% efficient is better than fueling up with gasoline.


I'm hoping these batteries do well. I've always liked the technology behind them. They are about the only "forever" battery. They were good enough for the Germans to use them to power their V2 bombs in WW2. 

Obviously, I was comparing their efficiency to other type batteries. The lower efficiency won't be a major concern for most EV applications but should be considered. It was a major concern for an off-grid application I was once working on. Even 80% efficiency for NiFe is a long way from the almost 100% charge/discharge efficiency of LiFePo4.


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## PhantomPholly (Aug 20, 2008)

Zappo said:


> I'm hoping these batteries do well. I've always liked the technology behind them. They are about the only "forever" battery. They were good enough for the Germans to use them to power their V2 bombs in WW2.
> 
> Obviously, I was comparing their efficiency to other type batteries. The lower efficiency won't be a major concern for most EV applications but should be considered. It was a major concern for an off-grid application I was once working on. Even 80% efficiency for NiFe is a long way from the almost 100% charge/discharge efficiency of LiFePo4.


I agree. The big thing to me is the improvement in surface area. I believe these batteries have the potential for much higher energy density if not using large thick flat plates, but they will probably never be ideal for EVs.


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