NIFE Battery Questions

Saggys

I have a chance to purchase 2 used sets of NIFE batteries.
Set 1 is a gently used 12 volt 100 amp hour that I thought I would use with our Morningstar suresine for lighting, fans and tv in our bunkhouse.
Set 2 is a used 24 volt 250 amp hour. I have reservations  about them being  able to start my well pump, it is a Grundfos soft start that draws about 8 amps ac out of our Trace PS2524 inverter.
Both sets come with material for electrolyte change, spare cells. These are Chinese cells marketed by one of the big distributors in the US.
My concern is the voltage sag under load that these batteries  exhibit.  I think system sizing maybe different than conventional Lead Acid batteries. 
We should have enough PV at 1800 watts for the 24 volt system.
What do the expert NIFE users think? Mike that means you!

706jim

(Mentioned previously) I was given about a hundred Nife cells salvaged from railway wigwags. They were a disaster and I was very lucky that our coast guard took them away as hazardous waste. Tremendous voltage sag and dismal capacity. ("But they're perfectly fine, the railroad just changes them out every ten years!")
I would buy something else if I were you.

Saggys

Thanks for the reply, I have some L16'S now that are starting to fail, so looking for alternatives.  Figured with a electrolyte change could refresh both.

Vic

Hi Saggys,

As you probably know,  member   "mike95490"  has run NiFe s for some time   ...   would listen to him,  on this subject.

You also know that NiFe batts are not in common use at all by the off-grid community,  for the obvious issues of: cost,  inefficiency,  poor surge capability,   necessity to change the electrolyte,  and so on.

Personally would avoid them,  even if free,  but have never run them.   Good Luck,   Vic

Saggys

What I do like is the fact they do not sulphate and you can freshen the with an electrolyte change. My inverter is rated to 33v input so I should be able to charge them, but if they can't start my well they are no use to me. My well shows 7amps ac on the inverter when running, verified after initial post.

BB.

If I understand correctly... The bags of KOH do require storage in a dry/cool area or the KOH picks up the moisture in the air... If the bags are left out for long periods of time/improper conditions, then it does eventually go bad (I think)...

https://blog.polyprocessing.com/blog/breaking-down-proper-potassium-hydroxide-storage

Anyway, beyond my knowledge.

Regarding your Grundfos pump, the standard models (I certainly do not know much about their lines) are "soft start"... So, the maximum run current is pretty much the starting current (internal VFD inverter with soft start).

-Bill

Saggys

That is correct Bill not much of any surge on startup, verified with my Fluke clamp on with inrush setting.
The owner of the batteries claims material is stored in a waterproof crate that is in a conditioned space.

mike95490

The flake electrolyte KoH, needs to be stored in a very dry space.   Water vapor, even at 20% humidity, will eventually penetrate the bags (remember how tough and how few materials  will seal a PV panel from moisture) and the flake KoH will be ruined.
 You also have to mix it with Distilled water to create the electrolyte and it is exothermic - it heats that water up to just under boiling, so your mixing containers have to withstand the water weight while hot.

I think the 24v  250ah bank would run the pump just fine, if it is indeed a no-surge start unit.

You can go to my facebook page, look for photo albums and find the NiFe Refresh page ( might be sub titled "battery inverter" because of the fixture I built to invert the batteries to drain them.   Took a helper and I a week, to empty, mix, re-assemble and refill the battery bank of 40 ( a 48v bank) 800ah cells.  Your cells will be much easier to work with, being much smaller.
 I also added my 2 spare cells to my main bank, to keep all batteries active (  why mothball good batteries that will need a re-commissioning regardless )

Saggys

Thanks Mike, I.can get these for.about $.33 on the dollar. The 250 amp hour bank was new in 2012, the 100 amp hour bank was new in 2015. The owner is getting older and moving on to lithium to avoid future electrolyte changes. I am interested and am happy to hear that they should start the well pump. Thanks for the input all.

Saggys

Contacted Zapp Works and they are not selling any batteries at this time. Looks like your choice at this  time is what's available in China. I was only able to obtain the 24 volt 250 amp hour set so I am looking into getting a 12 volt 250 amp hour set.

Saggys

6 month wait for 200 or 300 amp hour set from Iron Edison, no 250 amp hour available any more. They advised against mixing different battery capacity  in the same string, so I went with a 12 volt 100 amp hour set for our bunkhouse, these were in stock.
When I get all this sorted out and installed (might be awhile ) I will start a new post on how these work for us.

Photowhit

Did anybody tell you how inefficient these NiFe batteries are? 

mike95490

My bank runs about 70% or so, in efficiency.  Not great, which is a reason I added an extra 2kw of PV several years ago.

Saggys

Photowhit, thank you, well aware of inefficiency,  traded that for the ability to not have to worry about a full charge every cycle or so. My current lead acids have started to fail after 5 years ( some my fault parallel strings) and I kind of like the idea of being able to refresh the electrolyte as needed. Lithium ion is out of the question for us, outdoor battery box.

WDHaskins

Mike: We are running a 48 volt NiFe system of 2150 aH storage capacity. 38 cells. Working fine, but I would like to install something to measure the efficiency, to record separately the amps in and amps out. System was sold as 80 per cent efficient but I don't believe it. Any ideas what we need?

Photowhit

WDHaskins said:

Mike: We are running a 48 volt NiFe system of 2150 aH storage capacity. 38 cells. Working fine, but I would like to install something to measure the efficiency, to record separately the amps in and amps out. System was sold as 80 per cent efficient but I don't believe it. Any ideas what we need?

You can get a good idea of efficency by looking at the charging voltage compared too the nominal voltage.

Iron Edison makes 3 statements that pretty much can not be true;



If a 1.2 volt battery is charging at 1.65 volts, assuming the current doesn't suffer additional losses in thermal or chemical transition (pretty much impossible not to have additional losses), It's maximum efficency would be 1.2/1.65 or 72.7272...

Just my opinion, I don't think anyone else has claimed NiFe batteries are more than 65% efficient.

mike95490

Any shunt type meter can measure amps in and out.  Getting it recorded is another thing
  My 2 charge controllers record their output, and my inverter records it's loads, so that's where I get my efficiency guess from.   A lot goes into the batteries.  I've not done a lot of play with the absorb times to see if I can find the sweet spot.

Saggys

I would be very happy with 72.72 % efficiency.

Photowhit

Would you be happy with 65%? more realistic...

I've done well enough with 16.6 kWhs of lead acid battery for $2525 delivered, just slightly more now.... 10 years and it does need replacing, but should make it through the winter... And it was poisoned as a young battery... The poisoned cell is pretty much dead now. 

I'm likely to replace it with another, or rather 2, 12 volt as I'm not looking forward to moving the old one out (1100 pounds) at 62, It was hard enough to move in at 51.