Nickel-Iron Battery Designed for Extended Life

[TheClockmaker]

Nickel-Iron batteries are making a comeback in the renewable-energy industry. My personal interest happens to be for wind generator/solar power energy storage and also for a pendulum gear-driven clock design that I am working on where I need a minute amount of stored power to operate a small circuit board that will keep this mechanical clock in sync with an atomic clock.

Does anyone have knowledge how to extend the life of a Nickel-Iron battery? Can I just increase the thickness of the plates in a standard battery design?

Also, for my mechanical clock needs, is there a way in which I can change the design to be more of a large dry-cell or gell-cell design? My clock needs are at the level of a small AAA battery yet I want the clock to last more than a century if possible, and so I am seeking an unusual way to build some large plates that will last a long time. Perhaps by using some form of potassium hydroxide paste acting as the electrolyte?

Any suggestions or recommended reading is appreciated. Thanks.

 

[Eimacman]

I believe that the cells that you are referring to are Edison cells. Some of which have been in continuous use since 1909. I know of one large bank that was salvaged during the 1990's that were sitting around unused for nearly 80 years. They were rinsed with water and refiled with Edison's electrolyte a mixture of potassium hydroxide and lithium hydroxide. Upon charging voltage and current were comparable to new cells.

I have come up with several gel and glass mat designs none of which I believe will hold up to the test of time. Edison cells can be charged hard, drained until they are flat, subjected to extremes of hot and cold that would destroy conventional batteries. I believe this could be to their construction rather than chemistry though, although I am not sure about the LiOH in the original Edison electrolyte.

Edison cells also had one major drawback, they were of low energy density. So if you managed to get a AAA size Edison cell the current would be as small as a button cell.

 

[TheClockmaker]

...Edison cells also had one major drawback, they were of low energy density. So if you managed to get a AAA size Edison cell the current would be as small as a button cell.

I am just powering a small electronics board that sleeps most of the time and it generally only wakes up for about 2 minutes per day, unless it's time to change over to/from daylight savings; so I meant that my total energy needs are AAA battery size.

Although my needs are small I'm able to construct a rather large battery--about the equivalent of two or three large car batteries; therefore, I feel certain that I can make the battery last an extremely long time. I just need to figure out the best design that will not simply erode away due to time.

I am going to charge the battery from the constant pendulum swings by harvesting that energy using a coil (or coils) and permanent magnets. I suspect I'll use something like the Bendini motor/generator design, mainly because it's very simple, efficient, and it creates huge voltage spikes, which is great for charging a battery. I will have at least one magnet at the bottom of the pendulum swing, and perhaps up to three or five and possibly one at each end of the swing to harness more voltage spikes per swing. It all depends upon how much energy I need vs. what I can capture per coil.

My electronics, using fuzzy math, will micro adjust the clock speed and determine when to wake up should the battery voltage gain too much or too little voltage. If the batteries have too much energy stored then I can burn some excess of by rewinding the counter-weight, waking up more often to take readings, and as a last resort, I can burn it off with a resistor (which I doubt the logic will ever engage for use).

 

[Eimacman]

I would just use the original Edison design, and electrolyte. Being that very few Edison cells have ever failed due to age, one built on the original design should last 120+ years or longer with proper maintenance.

 

[gregor88]

hello,
check out http://opensourceecology.org/wiki/Nickel-iron_batteries and you will find gold there. please help with the project in return for this favor.