Nickel-Iron woes

Can not help you with recovering the cells as I use lead acid, however I have 12 budget 12v leisure batteries in a 24v series-parallel bank. Over time some pairs drifted apart in voltage. I added HA01 equilizers/balancers and over the following few recharge discharge cycles recovered useful capacity. My understanding is that in your situation you would have to use the HA02 version of the balancer, again my understanding is that its unlikely to recover your dead batteries but once you have fixed/replaced your dead cells it might reduce or stop similar problems in the future. My understanding is that the balancer effectively diverts currant to the cell/battery that is under charging it also works in reverse when discharging. NB to get the resolution on the added voltmeters I used a 10v zenor and resistor add 10v to the voltage displayed to get actual battery voltages.

HA01 balancer.jpg

Sorry for you battery issues. But I thank you for showing that most battery systems may only last about 3 years and still need to be monitored a lot to keep them "happy" and productive.

Hi,

I do not think that a balancer will help at all in my case. The problem is the gunk build up. I cannot see imbalance being the cause of that.

There is a method of regeneration that will create a build up:

Can't do that with mine, as this applies to original Edison cells, which have a metal case. Besides I have gunk, I don't need some more.

Possibly the electrolyte is at fault. This is what I am trying to find out. Maybe I'll never know, and end up with 40 new cells.

I don't think think this experience implies there is a problem with NiFes, or that they'll only last 3 years, just this batch. You only need to look at some of the other posts about them to see they can last a very long time, don't need to be thrown out out after 10 years, but can be regenerated. They do require a bit more work. I have usually only needed to top up the electrolyte over the past 3 years. It may be that the newer version of these cells isn't as good as the originals. But I haven't read of anybody else having any trouble. One user here has renewed his electrolyte after 7 years, but that was doesn't appear to be due to any failure, just did it sooner, rather than later.

Thanks,

dRdoS7

I've installed my 42, 800ah cells back in 2010 or 2011. In 2018, I did an electrolyte refresh (took a solid week of hard work), and they are still going strong.
I am very scrupulous about keeping cells sealed to prevent CO2 poisoning and only use tested De-ionized water for refilling. I've some terminal penetrations that developed some cracks, and those have been superglued closed. I closely monitor and log pack voltage daily Seller may have has a batch of bad cells, but it's not a NiFe normal situation.

Refresh pics: (Aug 2018)
https://www.facebook.com/pg/Lucky-Mo...13125788760863

Initial install pics (Oct 2011)
https://www.facebook.com/pg/Lucky-Mo...09715335768594

What does the battery vendor suspect causes the gunk buildup ? The Ni Fe plates do not exchange material like lead acid batteries do, so there is no plate shedding, Have you ALWAYS used pure water for refilling ? Did plates EVER get exposed to air ?

If this is the only example of a black gunk problem u can find from other NiFe battery users and I have asked two off gridders in the UK who use NIFE sorry they had not experienced the issue. But one said something about "the powder held in pockets on the plates had maybe come out, but thinks this only applies to one particular type of cell". I would think your next step should be to get a sample of the gunk to a lab and find out what it is. However I've emailed a couple of contacts I have (from when I explored using NiFe) to see if they have any idea whats going on, but both are Chinese manufacturers so given the currant situation in China I've no idea if I'm even going to get a reply. They are bound to ask who manufactured the cells.

More than likely there was impurities in the water which cause a reaction and the creation of sludge.

Hi All,

I saw & read you posts on here a while ago, glad mine are 200Ah.

Mine came filled, so all I had to do was connect them, and cycle them for 3 months. Took that long before they were working to full capacity. By mid May 2018 I had 80% efficiency. Currently it's around 60%.

I like the emptying rig. When it's time to renew the electrolyte, I'll make something similar, but with the axle between two cells so it's balanced. Also probably have a hose & valve in each so when upended it can be controlled. From what I've read: Empty 50%, shake a bit (cells that is), empty the remaining. No flushing, except with used, filtered old electrolyte.

I'd also do them in small batches (of 4) so I can keep using the inverter. That way I can take time, mix up small lots of electrolyte, etc.

Did you get anything (gunky) out of your cells?


He was supposed to contact his supplier (China), but hasn't said anything about it to me. He has said he will replace the 4 really bad ones. Don't know about future cells. We haven't got to that yet.

I bought some distilled water (20litres) from an auto spares shop after I installed the cells. Than I bought a distiller. I refill the containers that the DW came in, and also a few drinking water containers (10l & 15l) that I bought. I have about 130l all up Keep them tightly sealed. At worst they could absorb some CO2 while filling, or not completely full, but I don't think that would cause my problem, just create the carbonate which would be in solution in the electrolyte, not precipitate as black gunk.

Always reseal cells after filling. Never used anything other than my DW.

Yeah, I thought disintegration too. I'll let the seller worry about lab tests. He obviously thinks it's the cells, not anything I've caused. I know they come from China, that's all. When I've received the new cells, I'll send back the faulty ones. The seller can work it out with his supplier.

Not sure about "more likely", "possibly", maybe. I use a distiller, so I hope there's only DW going in to the cells. Any ideas as to what impurities it would need to be?

Thanks,

dRdoS7

If there was a way of getting a sample of the sludge it wouldnt be that hard to get it analyzed.

Hi,

I'll let the seller do that. He's going to replace some cells, then I'll send some back. I'm sure his supplier will be keen to know what it is as well! Or not.

If I ever find out, I'll post here.

I have almost a full 2 litre container of it, so yeah, not difficult. I've weighed it, and have about 2.5Kg. That's about 400g/cell (plus what's been flushed out and discarded). I suppose it's probably less actual crud, because it still has some moisture in it. Maybe I should spread it out to dry.

Thanks,

dRdoS7

While this stays with Nickel Iron batteries it does diverge from the black gunk subject and may be best in a new thread. I'm more than happy for it to be moved if the original poster and others want to.

Please could u expand on your statement "and cycle them for 3 months. Took that long before they were working to full capacity" particularly if u have any numbers over the three months period showing the starting point ie what % of full capacity did they start at and what technique did u use if different from a normal charging cycle.

"By mid May 2018 I had 80% efficiency. Currently it's around 60%." Could u clarify what parameter these efficiency %'s refer to, is it the charge/discharge efficiency?

Found this on another forum I'm not making any claim that its right or in any way useful, but may give a few leads for further investigation

Hi,

Ah readings from the WBJr I installed when I bought the NiFes. I reset the meter at the start of each run.

The inverter charging was disabled, as it would want to charge them when I didn't want them to (ie. overnight) which would ruin the results.

This is from the first month:

DATE Ah IN Ah Out %
16/11/2016 46 -10 22
17/11/2016 102 -20 20
18/11/2016 176 -43 24
19/11/2016 276 -72 26
20/11/2016 365 -106 29
21/11/2016 430 -130 30
22/11/2016 464 -165 36
23/11/2016 534 -192 36
24/11/2016 607 -210 35
25/11/2016 692 -229 33
26/11/2016 769 -244 32
27/11/2016 844 -260 31
28/11/2016 937 -291 31
29/11/2016 1033 -325 31
30/11/2016 1103 -343 31
01/12/2016 1179 -365 31
02/12/2016 1249 -406 33
03/12/2016 1345 -428 32
04/12/2016 1429 -461 32
05/12/2016 1532 -483 32
06/12/2016 1602 -594 37
07/12/2016 1703 -698 41
08/12/2016 1784 -804 45
09/12/2016 1836 -845 46
10/12/2016 1875 -884 47
11/12/2016 1917 -917 48
12/12/2016 1955 -952 49
13/12/2016 2013 -986 49

At the time I only had 3KW of solar. So it was limited, needing to supply house load, and charge them higher (1.7V/cell) than would be normal (1.65V/cell). Also, the maximum I could charge to was 60V (inverter trip point was about 62V).I also have a Midnite Classic which I can set to any voltage. I tried various battery wiring schemes grouped as 35-5, 38-2, 36-4, 39-1, This was to get the highest per cell voltage (without tripping the inverter), and be able to discharge them as low as possible (without tripping the inverter). In the end I found that by using a couple of solenoids, I had 2 take-offs, one at 40 cells, and one at 35 cells. A voltage controller was set so it swapped between them, keeping within inverter limits. The MN Classic charged all 40 at about 67V, the inverter ran on 35 cells when charging, and 40 cells when discharging. Worked rally well, I bought a new inverter in 2018, with slightly a higher limit (64V alarm, 66V trip), and reverted to 40 cells.

These are readings after 6 months. The first few are a bit suspect - but that's what the readings were. The ones in the 3 days before that were in the 70s. Don't know for sure, but it may have been cloudy and not much going in:

DATE Ah IN Ah Out %
14/04/2017 42 -64 152
15/04/2017 91 -111 122
16/04/2017 145 -166 114
17/04/2017 185 -203 110
18/04/2017 351 -267 76
19/04/2017 441 -358 81
20/04/2017 537 -445 83
21/04/2017 551 -508 92
22/04/2017 651 -583 90
23/04/2017 697 -643 92
24/04/2017 768 -704 92
25/04/2017 802 -745 93
26/04/2017 890 -819 92
27/04/2017 931 -865 93
28/04/2017 1003 -931 93
29/04/2017 1069 -991 93
30/04/2017 1083 -1010 93
01/05/2017 1177 -1050 89
02/05/2017 1248 -1126 90
03/05/2017 1307 -1178 90
04/05/2017 1445 -1241 86
05/05/2017 1553 -1323 85
06/05/2017 1603 -1407 88
07/05/2017 1702 -1477 87
08/05/2017 1807 -1551 86
09/05/2017 1849 -1611 87
10/05/2017 1993 -1680 84
11/05/2017 2041 -1757 86
12/05/2017 2135 -1843 86
13/05/2017 2228 -1910 86
14/05/2017 2328 -1992 86
15/05/2017 2403 -2058 86
16/05/2017 2451 -2116 86

These are the reading after 12 months.

DATE Ah IN Ah Out %
27/12/2017 171 -124 73
28/12/2017 237 -218 92
29/12/2017 268 -259 97
30/12/2017 380 -342 90
31/12/2017 577 -466 81
01/01/2018 710 -579 82
02/01/2018 844 -686 81
03/01/2018 985 -815 83
04/01/2018 1161 -956 82
05/01/2018 1341 -1097 82
06/01/2018 1483 -1231 83
07/01/2018 1620 -1346 83
08/01/2018 1768 -1460 83
09/01/2018 1942 -1570 81
10/01/2018 2086 -1695 81
11/01/2018 2247 -1827 81
12/01/2018 2259 -1869 83
13/01/2018 2334 -1934 83
14/01/2018 2508 -2052 82
15/01/2018 2632 -2169 82
16/01/2018 2828 -2276 80
17/01/2018 3007 -2393 80
18/01/2018 3165 -2553 81
19/01/2018 3330 -2674 80
20/01/2018 3474 -2804 81
21/01/2018 3618 -2948 81
22/01/2018 3791 -3060 81
23/01/2018 3971 -3179 80
24/01/2018 4119 -3299 80
25/01/2018 4270 -3424 80
26/01/2018 4325 -3489 81
27/01/2018 4448 -3608 81
28/01/2018 4595 -3731 81
29/01/2018 4637 -3787 82
30/01/2018 4744 -3874 82
31/01/2018 4873 -3977 82

Hope that answers your questions.

I stopped taking reads for a while, but started again when the failures began.

Last 5 days:

Date--------WBJr WBJr Classic Classic MPP In Out %
---------- AhIn - AhOut Total ---- In - In
03/02/20 64528 -35058 205595 101 60 161 87 54%
04/02/20 64655 -35142 205676 81 46 127 84 66%
05/02/20 64788 -35221 205757 81 52 133 79 59%
06/02/20 64920 -35303 205834 77 55 132 82 62%
07/02/20 65088 -35387 205906 72 96 168 84 50%

Pasted table doesn't work very well.

Tried a forum table, but have to enter data manually (that sucks - & prone to errors) Looked OK when I did it, but went weird once it was posted!!??


Thanks,

dRdoS7

Pasted tables never seem to work on forums.Thanks very much that's a great set of numbers to help make a decision between NiFe and lead acid, plus an idea of what numbers I need to auto collect so I can monitor things. What I've got now just runs my low usage stuff I have two generators a diesel 3phase and an LPG 13kva but only use the LPG as part of the 24v solar system that is in the order of 10% model of the final plan. I'm looking to build a system to run all the future plans for my workshop using three inverters to make 3 phase. My workshop is totally off-grid we use composting toilets and rain water. I have a usable 300 sq meters of roof (out of 700sq meters facing 100 degrees not ideal but OK so a potential of around 180 panels. I was intending to go to China and to build the necessary contacts to source everything I need for this and another project but that's now on hold for obvious reasons. I found some references to gunk in NiFe in another forum but 'I may be being stupid' but can not find a way to PM u with links.