still in use after many years are in low-current-demand applications.
These pre-dated the Lead-acid battery, and were made
obsolete for automotive use by the Lead-acid battery. NiFe batteries retain a very small niche in safety critical equipment used underground.
Disadvantages of NiFe:
Lower energy capacity and
energy-weight ratio {crucial for transportation applications} than Lead-acid.
Much lower maximum current drain. High self discharge current (they go flat even without being used in a few weeks).
Advantages:
They last “forever” and are not damaged by short circuit, by being left discharged, by being over-charged (you just top up the electrolyte). The raw materials (Nickel, Iron, caustic Potash) are cheap and less polluting than Lead acid if a spill happens.
I cannot help thinking that the NiFe battery should be looked at again, for large scale storage of solar power. The advantages are all positives for this role, especially the long life. The disadvantages are small for something that is recharged daily and installed in a fixed location that can be as large as it needs to be.
https://www.quora.com/Is-there-such-a-thing-as-a-battery-that-lasts-100-yearsOne thing to look out for is that the electrolyte is a solution of potassium hydroxide (KOH) which absorbs CO2 from the air, forming the weaker base, potassium carbonate (K2CO3). Sealing the battery, or providing some sort of active filter, is essential. I'm sure it could be worked out for stationary applications, such as grid storage. But it's no "hidden secret", by any means. Anyone who knows battery tech knows about the Edison Cell, as it's been known for over a century. No over-the-top CT hype needed -- and it's misleading.
Also Google "
https://www.google.com/search?client=safari&rls=en&q=what+is+longest-lived+variety+of+battery&ie=UTF-8&oe=UTF-8" to compare all cell types, including some you've never heard of.
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