Nickel Iron batteries

JonCombat

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Jan 11, 2022
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Has anyone built their own or purchased used Nickel Iron batteries? They require maintenance and the power density is low but they can last a life time!
 
i have a couple ones laying around from old laptop batteries
at some point, i do wanna mess with them, but not right now

why do you think, that they can last a lifetime? their memory effect is pretty severe and they dry out over time

//edit
nvm, i thought you meant nickel hydrate batteries

From what i'm reading, they behave like lead acid batteries, except they dont sulfate or similar when discharged, so they dont loose capacity due to being discharged to any point. But they need to be refilled with water every couple of weeks, loose charge over time and are similiar inefficient like lead acid while being charged. Defenitly a neat old technology and they can be usefull for certain scenarios, but i find lithium batteries leagues better for a powerwall.
 
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they can last a life time!
This is subjective. What is considered a "life time"? 1yr, 5yr, 10yr, 20yr ?????

And to be honest, "everything" lasts a life time.
 
i have a couple ones laying around from old laptop batteries
at some point, i do wanna mess with them, but not right now

why do you think, that they can last a lifetime? their memory effect is pretty severe and they dry out over time

//edit
nvm, i thought you meant nickel hydrate batteries

From what i'm reading, they behave like lead acid batteries, except they dont sulfate or similar when discharged, so they dont loose capacity due to being discharged to any point. But they need to be refilled with water every couple of weeks, loose charge over time and are similiar inefficient like lead acid while being charged. Defenitly a neat old technology and they can be usefull for certain scenarios, but i find lithium batteries leagues better for a powerwall.
maintenance is not an issue, replacing lithium-ion batteries every 5-10 yrs can be expensive. If used for a fixed solar system and space/weight is not an issue I think they would be ideal. Since the power density is not their for in-rush loads I wonder if you can create a hybrid battery setup and add some lithium batteries to help supply the in-rush current when a compressor/AC is turned on.
 
Feel free to build a system based on them and report back on how it performs. It would defenitly be an interesting topic at least and its the first time, that i heard of those batteries.
 
The cost of nickel iron batteries is insane. I guess there is not much profit to be made if you make a battery that lasts decades! They have been around for 100+ yrs
 
They contain a lot of material and aren't a very demanded product, so yeah, the price isnt cheap. Maybe you can find some second hand ones.
 
Lithium Tinanate datasheet https://files.gwl.eu/inc/_doc/attach/StoItem/6991/LTO-40AH-CY_datasheet.pdf so LT) has many of the same properties as NiFe batteries. long life being the key one 30,000 cylce life time works out to be 82 years<edit>@1 cycle per day. < first datasheet I found.
Maybe you can find some second hand ones.
I saw some 4 or 5 years ago on Ebay. Used not just one cell. like is on ebay now. The new ones on ebay work out to $659 a kWh of storage.
 
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Nickel iron (edison) batteries are probably one of the most durable and stable batteries available but they also have downsides compared with Li-ion: Capacity per volume/weight is low (ca. 20 Wh/kg) - which is 1/10 or less of Li-ion, voltage is lower (1.3V/cell), price is high. The Pro's are: durability (lifetime?), no damage by deep discharge, overcharging rather similar to lead acid or NiCd, maintenance similar to lead acid, quite safe to use.

The electrolyte is potassium hydroxid solution which must be sealed against CO2 from the air, otherwise the electrolyte will carbonize. Its temp. must be controlled during charging with high amperage (max. 45 deg. C).

Hard to find and expensive and not state-of-the-art for PV usage due to lack of capacity resp. heavy weight and cost.
The cycle life is probably between LiFePO and LTO (4000 - 8000 depending on usage).

I definetly would prefer LiFePO (comparable durability but much better energy density, light weight, higher voltage, high drain capabilities).
 
If you want to build some cells your self, i think you want to look for ("solid state") zinc bromine cells.
 
Another disadvantage of the Nickel iron one is the inefficient energy cycle, Lithium type get you late 98%+ round trip (charge to discharge) so you need more input for the same output.
Pretty much any other battery tech that needs physical maintenance (water/electrolyte top-ups/changes) is on the back foot compared to Lithium which just works.
 
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