Nickel-Iron woes

[dRdoS7]

Hi,

Does it come with a BMS (a complete BMS, over, under, full, cold, hot) and a way to integrate it with your charging source ? If the BMS cannot control your charger, it's the wrong one.

I've bought a BMS, it does what a BMS does.

The BMS has an RS485 connector, but neither of my devices, SCC nor Inverter, have any method to allow them to be controlled. Any out-of-spec values will cause it to shut off the bank to them both.

Thanks for your input.

NiFes go back next week.

dRdoS7

[Mike90250]

Hi,

.......................

I've ordered 18 x 280Ah LFP. What could possibly go wrong?

Thanks,

dRdoS7

Does it come with a BMS (a complete BMS, over, under, full, cold, hot) and a way to integrate it with your charging source ? If the BMS cannot control your charger, it's the wrong one.

[dRdoS7]

Hi,

Been a while. The 6 cells I was expecting didn't arrive. I contacted the seller in June. He told me they weren't holding a charge, and didn't want send them. He said he had more coming, and would send 10. No contact for a few months. Called him last week and told him I wanted to return the cells, and get a full refund. Left it at that, called again Monday, and he agreed. He is going to refund 50% this week, and the other 50% when I return the cells, at his expense. So my NiFe adventure is over (hopefully). Sadly, it didn't work out as planned. They worked wonderfully for about 2 years.

I've ordered 18 x 280Ah LFP. What could possibly go wrong?

Thanks,

dRdoS7

[dRdoS7]

Hi,

Hi

Do you know what the correct weight for the cells should be, is it 12900 or 12400 , If its the lower weight that might suggest impurities had got in and maybe cell 6 with no debris has already been compromised but not yet developed the debris, maybe its been over filled. Long shot I know but just throwing a few thoughts into the mix, as usual with anything that goes wrong it may be a combination of things. Given new cells are arriving soon which will get u back up and running an explanation may never be found. Let us know how u get on with the new cells

According specs, each cell should weigh 14Kg filled. Possibly they've been on a diet! Possibly the manufacturer has overstated that, or it was for the first few production runs, but has been reduced to save them money. Cell size is the same as in the specs.

One good cell weighed 12973g, and one that hasn't been cleaned is 12894g. The two low weight cells (previous post) have been cleaned. That is some slimming program.

I spoke to the seller, and he has new cells in stock. He's going to charge them, and send me 6 new ones next week. It will be interesting to weigh the new ones, and compare them to the originals.

None have ever been overfilled. Nor have they been allowed to drop below the minimum line. I want to protect my $8000 investment. Though some got very close. I check them a couple of times a week, so I have an idea of when they'll need more water. If we're going away, top them up a day or two before leaving. That doesn't happen much as I usually turn everything off. I'd spend the time away worrying about them running dry for some reason. It's OK for a couple of weeks though, I drop the charge settings a bit. Not much is running if we're not home.

I was reading through the emails I sent the seller, and saw this:

When I had the faulty cells on the floor, I noticed some grey matter in the bottom of both cells. I've attached a photo of each one. I one it is up to the separators, the other double that height. None of the other cells that I can see, are like that. 19 are on 2nd. row of shelving, and behind the first 19, so I can't see the bottom of those.

That was almost 2 months after the first email about low cell voltages. So the rest of the cells have been deteriorating since that date (early June 2019).

Thanks,

dRdoS7

[Iansworkshop]

Hi

Do you know what the correct weight for the cells should be, is it 12900 or 12400 , If its the lower weight that might suggest impurities had got in and maybe cell 6 with no debris has already been compromised but not yet developed the debris, maybe its been over filled. Long shot I know but just throwing a few thoughts into the mix, as usual with anything that goes wrong it may be a combination of things. Given new cells are arriving soon which will get u back up and running an explanation may never be found. Let us know how u get on with the new cells

[dRdoS7]

Hi,

Just a quick update:

I've weighed a few of the cells to see what the difference is between those with no debris, those with debris, and those that have been flushed and renewed.

Condition	#	Weight (g)
Has Debris	7	12894
No Debris	6	12973
Cleaned & Renewed	8	12420
Cleaned & Renewed	18	12447

The cells that have been cleaned lost about 450g. That tallies with the amount I recovered.

According to the seller, the cells he ordered have arrived in port. Said it would probably take another week before he has them.

Thanks,

dRdoS7

EDIT: Tables not working to well here. I've as well.

cell weights.jpg

[dRdoS7]

Hi,

When rigging up a scheme to add and remove batteries from a bank for charging and discharging (to keep from over voltaging an inverter) you end up overcharging some, and undercharging others.
What else can I say.

The failed cells are from various parts of battery bank, so I don't see it has any bearing. The crud is also in 37 of 40 cells. The ones without are also spread around.

overcharging cells should have only consumed more water, but if they started getting hot, that's never good.

Why did you feel it was ok to over-voltage the cells while charging (1.7v vs 1.65) ?? Did the battery vendor instruct you to do that ? Was the vendor aware you were switching cells in and out? These are all RED FLAGS that you contributed to the demise of you cells.
Here's a trophy

The cells were already failing, and had crud in the bottom, before changing from normal charging settings.

None of the cells ever got hot. I had a temp sensor on one, and that got to 31C. A couple of cables did get very warm though, could still hold them.

The seller told me to charge them at a high voltage to see if it fixed the faulty ones. It does actually appear to have fixed one that didn't have a flush and electrolyte replacement, and 2 that did (probably only temporary). I'll see when the 4 really bad ones are replaced.


But anyway, thanks for the award, which I really do not deserve. I'm sure there are some worthy candidates.

I do believe I should get a Darwin Award, or at the very least an Honorary Mention, for the one I 'sploded.

Thanks,

dRdoS7.

[dRdoS7]

Hi,

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

1. Take a few ml of electrolyte out of one of the cells
2. Add water to electrolyte to form gunge
3. Take some more electrolyte from the cell and add to gunge until it starts to dissolve
4. Leave in air and see if it goes orange around the edges

This isn't an exact procedure and you may need to fiddle about a bit

Explanation

Earlier in the thread I seem to recall that you washed out one of the cells with water and ended up with loads of grey gunge? When a NiCd or NiFe battery discharges Hydroxides of whichever metals are present are formed. These are soluble in the Potassium Hydroxide solution but not in water.

I was thinking that if you take a small amount of battery electrolye it will contain the Hydroxides of Nickel and Cadmium or Iron depending on the type of battery. If you take a few ml of this and add water you should get the gunge forming. If it is a NiFe battery there should be Iron II Hydroxide in the gunge which you can test for Iron content.

I don't know what the gunge looks like - if it's lumpy you could catch a lump and put it into a small container and add a little more electrolyte (which you haven't added water to) from the battery to make it just begin to dissolve again. If it isn't lumpy just add a bit of electrolyte anyway.

In an alkaline solution (which you have created by adding the KOH in the electrolyte) any Iron II Hydroxide in the gunge will be oxidised to Iron III Hydroxide which is orange. If there's iron present it should start to happen around the edges where the gunge is in contact with the air

I missed this earlier.

The gunk in my cells is already visible in the bottom of the cells. That's how I knew there was some, even before change the electrolyte.

Thanks,

dRdoS7

[Iansworkshop]

Hi,



Just post them as a reply here, that way others can use them too.

Thanks,

dRdoS7

I've applied to join the forum at navitron.co.uk but have yet heard back yet I think because they ask for a real email address i.e not hotmail gmail etc it appears that some members on this forum get a bit 'hot under the collar' but however try this link https://www.navitron.org.uk/forum/in...html#msg187870

[Mike90250]

When rigging up a scheme to add and remove batteries from a bank for charging and discharging (to keep from over voltaging an inverter) you end up overcharging some, and undercharging others.
What else can I say.

overcharging cells should have only consumed more water, but if they started getting hot, that's never good.

Why did you feel it was ok to over-voltage the cells while charging (1.7v vs 1.65) ?? Did the battery vendor instruct you to do that ? Was the vendor aware you were switching cells in and out? These are all RED FLAGS that you contributed to the demise of you cells.
Here's a trophy

[dRdoS7]

Hi,

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.

Just post them as a reply here, that way others can use them too.

Thanks,

dRdoS7

[Iansworkshop]

Hi,

Hope that answers your questions.

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

Pasted table doesn't work very well.

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.

[dRdoS7]

Hi,

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?

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.

Date	WBJr In	WBJr Out	Classic Total	Classic In	MPP In	In	Out	%
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

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

[Iansworkshop]

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

4 Energy/Electricity Storage and Use/Grid Connection / Off-Grid, Batteries & Inverters / Re: Nickel Iron Batteries on: February 08, 2012, 04:57:55 PM

Started by Heinz, Message by Eleanor Relevance: 2.6%

Oh dear, sorry, clear as battery gunge! 1. Take a few ml of electrolyte out of one of the cells 2. Add water to electrolyte to form gunge 3. Take some more electrolyte from the cell and add to gunge until it starts to dissolve 4. Leave in air and see if it goes orange around the edges This isn't an exact procedure and you may need to fiddle about a bit Explanation Earlier in the thread I seem to recall that you washed out one of the cells with water and ended up with loads of grey gunge? When a NiCd or NiFe battery discharges Hydroxides of whichever metals are present are formed. These are soluble in the Potassium Hydroxide solution but not in water. I was thinking that if you take a small amount of battery electrolye it will contain the Hydroxides of Nickel and Cadmium or Iron depending on the type of battery. If you take a few ml of this and add water you should get the gunge forming. If it is a NiFe battery there should be Iron II Hydroxide in the gunge which you can test for Iron content. I don't know what the gunge looks like - if it's lumpy you could catch a lump and put it into a small container and add a little more electrolyte (which you haven't added water to) from the battery to make it just begin to dissolve again. If it isn't lumpy just add a bit of electrolyte anyway. In an alkaline solution (which you have created by adding the KOH in the electrolyte) any Iron II Hydroxide in the gunge will be oxidised to Iron III Hydroxide which is orange. If there's iron present it should start to happen around the edges where the gunge is in contact with the air

[Iansworkshop]

Hi All,




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%.



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?