Nickel Iron vs. Lead Acid - Off Grid battery debate

[J.P.M.]

Perhaps. I spoke to Iron Edison at SPI and they didn't seem at all to be marketing hypesters. In fact the technical guy there warned me about assuming that nickel iron batteries were a drop-in replacement for any other kind of battery.

Somehow this seems to have gotten off the rails.

My comments to KIRK1's comment was meant to suggest that if he believes "there's right now a host of Fe-Ni vendors in china so somebody must be buying Fe-Ni batteries" (according to who, BTW ?) he may be a victim of the same type of marketing hype that Musk tries to pull off with is production capability fantasies and projections. That is, China MAY have all sorts of production capacity, but China MAY also (or rather) have a goal of making folks think they have all sorts of production capacity that they in fact do not have, and/or/also that would like folks to think sales are greater than actual for reasons of their own. Or, there may indeed be a boatload of vendors who aren't producing as much or as profitably as they'd like everyone to think.

Then too, the idea that there's a lot of Fe-Ni Chinese batteries sold seems to be an statement that could use some verification and context.

[Mike90250]

Well, I have a chicom set and bought it via BeUtilityFree.com I don't plan on buying another one. I think they have a lot of domestic use in China

[littleharbor]

I don't plan on buying another one.

Is this because you are happy with them, or because you aren't happy with them?

[Sunking]

I've followed the Fe-Ni battery saga for a year or so: i believe if anyone is going to compete with energy trusts, it would have to be with such batteries.

There's right now a host of Fe-Ni vendors in China: so somebody MUST be buying them.

Then you must be a fool or Chi-Com? Edison never renewed his Patent and it expired in 1940's, Edison Electric sold the plant to Exide in in 1972, and production ceased in 1975.

Due to its low specific energy, poor charge retention, poor charge/discharge efficiency, high maintenance, and high cost of manufacture, other types of rechargeable batteries have antiquated NiFe batteries.

There only real application that can be justified is in Mining Industry for emergency lightning where batteries are exposed to high temps, heavy vibration. slow charge/discharge, efficiency and cost is of no concern.

[Mike90250]

Is this because you are happy with them, or because you aren't happy with them?

I'm happy enough, spent the $$$ already, and re-rejuvenated the electrolyte this last summer, still going and I never worry about sulfation destroying them in a week. But they are inefficient thirsty bastards

[johnpearcey]

Hi everyone,

I am interested in learning if you have any experience with non-traditional battery systems?

Is anyone using ni-cad or nickel iron? I am looking into Nickel Iron (ni-fe), anyone currently using these?

Thanks!

I'm currently using NiFe off-grid. Just changed over from lead-acid. Lead-acid are not actually cheaper despite what people keep saying. The capital outlay is more for equivalent *quoted* Ah. The problem with lead-acid is that you can't effectively use more than 20% of the quoted capacity. But with NiFe you can use all of it. So NiFe is 5x more useable capacity straight off. Not to mention that lead-acid plates disolve pretty damn quickly. They can be dead in 1 yr with daily cycles. I've been quoted at least 15 yrs for my NiFe by the manufacturer.
Also, if anyone needs to reduce the voltage to their inverter by 1 or 2 volts, a method I use is to add 2 or 3 forward biased diodes between the batteries and the inverter. It's not a particularly efficient method but it works. I charge my (38) batteries at 66v from either solar or genny and 3 diodes drop the voltage to 63.75v to the inverter, since my inverter cuts off at a little over 64v.

[johnpearcey]

I'm happy enough, spent the $$$ already, and re-rejuvenated the electrolyte this last summer, still going and I never worry about sulfation destroying them in a week. But they are inefficient thirsty bastards

What efficiency do you reckon? I have a computer monitoring my batteries and logging the parameters every 5 secs. From my calculation so far, I seem to be getting 77% charge/discharge cycle. Interestingly though, there seems to be a dead level - the first 0.9amps charging contributes nothing. Can anyone else confirm this?

[Ampster]

What efficiency do you reckon? I have a computer monitoring my batteries and logging the parameters every 5 secs. From my calculation so far, I seem to be getting 77% charge/discharge cycle. Interestingly though, there seems to be a dead level - the first 0.9amps charging contributes nothing. Can anyone else confirm this?

Is that just the battery efficiency or does that include losses through the charger and inverter?

[johnpearcey]

Is that just the battery efficiency or does that include losses through the charger and inverter?

Just the battery.

[Mike90250]

I have no way to separate the battery consumption from the load consumption, so I don't have a efficiency #. I do log my inverter usage and solar consumption, and factor about 50% end-end efficiency, here's my #'s from a while ago. (screenshot includes a day with smoke from fires.)

example, oct 1st, I harvested 16.1kwh, and consumed 9.088kwh, leaving 7kwh of system losses, most of which (5kwh?) is likely the NiFe batteries, the rest being heat in the inverter and 2 charge controllers.

RedwoodFire_SmokeProductionLoss_10-2017.jpg

[johnpearcey]

OK, so my previous comment about 77% for the batteries was actually the charge efficiency, not the energy efficiency. My mistake. So I have done a bit of work this morning and come up with an energy efficiency. This is very early days (in fact only 6 days worth of data at this point) and I will post an update in a few weeks time. The energy efficiency curve is heading towards 50% very roughly. My batteries started empty and I'm accumulating charge as I go so I expect the curve to be heading upwards and to level out in a few weeks time. I'll try and upload an image - not sure how this will work out. Black is voltage, blue is amps, green is charge estimate (Ah) and grey is efficiency (ignor Orange)
Screenshot from 2020-02-27 10:14:22.png

[Mike90250]

First, I have to mention someone else was undercharging their NiFe and may have ruined some of their cells.

But the question is why are you unable to charge the cells properly ?

[johnpearcey]

First, I have to mention someone else was undercharging their NiFe and may have ruined some of their cells.

But the question is why are you unable to charge the cells properly ?

Unlike lead-acid, I can't see any reason why undercharging might be particularly harmful to NiFe. Is there some chemistry at work here that I'm not aware of?? I must admit that chemistry was never my strongest subject!

So, sunshine is not very abundant here in Ireland. I'm figuring on running along with 50% charge using diesel only if I really need to. Then if a sunny day comes along, there'll be plenty of storage room available. Solar charging here is starting around 9am and finished at 4pm and I get about 30Ah in that time (37% full). So it might be worth me running at 50Ah at this time of year (I have total of 80Ah capacity)

[Mike90250]

The cells, when new, need a conditioning or forming charge, which is similar to an activation charge for FLA batteries.

Here's an excerpt from my manual:
Chapter 3: First Charging and Storage
3-1 Pre-charge Preparation
3-2 Charging Procedures
3-3 After-care of First Charging
3-4 Storage of Charged Cells

Installed and connected properly the battery should be fully charged as soon as possible. Before
proceeding to charge, check the AC or DC battery charging power source and the battery charger

1) For the first charge, the charging should be continued for 8 hours with the indicated constant current.
The first charge is a 200% of the C/5 rating Appendix D. For example, if your battery bank is a 500 AH
(at C/5 rating), divide the 500 by .25 which is 125, then charge for 8 hours. If you cannot charge your battery bank at the Ah called for then you can charge at less amp hour but you will still have to put in the correct amount of Ah into the battery bank, but will have to cycle your battery bank 2-3 times to have battery bank reach full capacity.
2) This first charge should be done (but does not have to be) with a controlled charge source such as
a inverter battery charger, a DC charging source or a battery charger plugged into an AC generator.
If you use a solar array it could take days or even weeks! So we suggest a CONTROLLED charging
source and not a PV array. If you are changing out an old battery bank we suggest that you cycle the new cells before removing the old battery bank.


If you did not get a manual, I could email a copy of mine to you. There is useful info in the manual, it's more complicated than just hooking up.

[johnpearcey]

Hey Mike90250, very much appreciate your help.

I bought my cells from China and the 'manual' was a little sparse on details. There was mention of a forming charge (I think it was 12 hrs) but I thought I might be able to do that on the fly so to speak. I was under pressure to remove some really dead lead-acid batteries so I was taking shortcuts. Maybe I should hit the generator now for 12hrs and give them a good blast?

And I'd very much appreciate a copy of that manual, thank you.