Need some help with settings after an extended grid outage on Friday

midwesteddie · March 2023

Hi al,

I'm still learning my way. All of these questions are regarding a system that was installed in a home that we purchased about 4 years ago (and were given no instructions).

I think my signature describes most of my equipment. It's an older system with 38 (connected + 2 additional batteries are not connected to the bank but are numbered as if they were once part of the bank) Ni-Fe batteries (1.2v, 400ah).

At about 3:34 PM on Friday (3/3) the grid went down. At about 5:23 PM the battery bank dropped below the LBCO setting of 40.0V (killing power to loads that were still on). After the appropriate delay, the AGS started up our Generac, but it only ran for maybe a minute or two the first few times and the batteries depleted very very quickly. Eventually, I was running around shutting off circuits that were not essential, in an attempt to lengthen the cycle of "charging" the batteries, but it never really worked as I would have expected. (see image) We actually left for a bit (due to lack of power) and until about 11 p.m. When we returned I tried tweaking some settings in an attempt to get a better charge on the batteries (increased the , but never really felt like I figured it out. Grid power was restored around 1 AM so I wasn't able to experiment anymore.

Again, this did not seem ideal. One of the bigger annoyances was the loss of all power in the gap when the batteries kicked off and the generator charging them back to an acceptable/usable (however temporary) level and this just kept repeating. Ideally, the generator could kick on before everything shuts off so our backup power would be comparable to having a generator running non-stop (uninterrupted power).

I have detailed logs of the original settings, but I don't know which settings would be helpful.

The reference to SOC below is a little misleading. It's not charted. I'm colorblind and SOC and Voltage look like the same colors to me, but I suspect they are different.

Also, this does not relate to the enPhase equipment listed in my signature it's this stuff: Ground-mounted (hybrid?) system with 40 Changhong 400 Ah, 1.2V Nickel-Iron batteries, 24 Kyocera KD210GX-LPU, 2x Schneider Electric Conext XW 6048 Inverter/Charger, 2x Xantrex XW-MPPT60-150 Solar Charge Controller, Schneider Electric Conext XW+ System Control Panel, Schneider Electric Conext XW+ Automatic Generator Start, Schneider Electric Conext ComBox

Image: https://us.v-cdn.net/6024911/uploads/editor/68/u6hbff5dwe21.png

BB. · March 2023

Unfortunately, I do not know much about the details of your system... But it does appear that your batteries are either not being charged to capacity, and/or they are in need of reconditioning (new electrolyte, etc. needed for NiFe type cells).

The complexity is that you have several charging sources (solar, AC mains, genset...?). And you need to ensure each is programmed correctly. There is also the issue of how the system is configured... Does the XW inverter-charger control all the charging, or does the MPPT Solar Controller control charging (during the day), and the ivnerter-charger controls genset/AC charging when the sun is down (and/or under heavy loads).

Looking at the upper line--The Current--there is little current being used (relative to a 400 AH @ 48 volt battery bank), and yet the battery voltage is falling rapidly. Sign that the battery is under not fully charged and/or the battery capacity is low (need electrolyte change?).

There are also peaks of charging current (night/genset?) of 80 amps... And the battery voltage also spikes (low capacity or is this "normal" for NiFe batteries--I do not know). In either case, the charge controller (the inverter/genset control) is not holding charging for a few hours, but just minutes or even less... To property charge these batteries, they will need hours of on-charge time (absorb phase) to properly recharge.

You are probably at a crossroads here... Do you (I suggest) hire a knowledgable person to go over your system, check the programming, and the condition of the NiFe batteries (this will probably take at least a day to a few days) and do the NiFe battery electrolyte change... Or do you get new batteries (Lead Acid of some sort, or even Li Ion--$$$), or what.

Your system is older now... There is no factory support to speak off (Dave said you were a couple generations of hardware down?--No firmware upgrade path for existing hardware, no factory spares)... Do you spend the money/time/effort on the existing system (which seems to be functional but towards end of life for major components such as inverters, replace NiFe batteries with new bank, new chemistry?)... New hardware (inverter/charge controllers/networking devices) and keep the (labor intensive and relatively inefficient NiFe batteries)? Lithium batteries ("nearly" the ideal battery type--long life, very efficient, no maintenance)--But probably would need new hardware to properly support the Li Ion batteries (ideally close loop system--Li Ion battery monitoring system BMS communicates with upgraded inverter+controllers to insure batteries are operated for best life, best performance, and avoid possible lithium bank destruction from over/under voltage/charging/loading, etc.).

And get training/documentation from the engineer/consultant on how too keep your system running and do the required maintenance.

I don't think you can do "nothing". The system is obviously not meeting your needs now (an hour or two of backup battery power). Need to review configuration to make sure you are not "wasting" utility power "floating" your NiFe batteries (at least make sure solar is properly configured and functioning).

As the system is running now--Your generator is cycling several times an hour(?). Batteries are providing almost no useful energy. You may be wasting grid power on your battery bank)... At best, when the grid is up, and sun is shining, your system may be feeding energy back to the grid from solar (at least making a bit of money when the grid is OK).

If you choose not to put a bunch of money into your system now... Your next choice is probably to mothball the system. Setup the genset to run a a normal backup power source (i.e., grid goes down, genset starts and runs until power returns). If you only have a few hours or a couple of days a year of power failures--This is probably the most cost effective solution (at least for now).

As a step too--If you choose to forgo solar backup/off grid power--You could probably take the existing array an purchase a new GT Inverter and wire the new (relatively inexpensive) GT inverter to the array and get some benefit from the otherwise unused array (assuming the array is still functioning well at this time--Something else to check).

If nothing else, mothballing the existing system and using the genset for backup power--That will give you months (or longer) to do more research and plan your next system.

Off Grid/Hybrid solar systems can be complex (like yours) and they take maintenance + money to keep running. I suggest that electronic hardware has a 10+ year life (sure, can go 20+ years--But many do not). Figure out the costs of Off Grid/Hybrid solar system is worth it for you and your family.

I am very sorry I do not have the knowledge to help you with your system. I just do not have the training or detailed knowledge needed. My suggestions are nothing spectacular. But you do need to have a plan to move forward. Just leaving the system "as is" will not be a sustainable long term plan (I fear).

Sincerely,
-Bill

midwesteddie · March 2023

Thanks for the reply. I agree with virtually everything you wrote/suggested. We spent months and months trying to find anyone who could come out and assess/document the entire system/configuration and we were never able to find someone who could help (we haven't stopped looking for someone-but have kind of lost hope in finding someone). We have asked large local commercial electrical companies, etc. I have contacted the sustainability folks here at the university that I work at and even some local Facebook groups. Basically, I will let anyone who is willing to come out and look/help try.

Perhaps, I'm also not finding much help because I keep asking in the "Beginners" group because I consider myself a beginner. However, I'm not exactly asking "beginner" questions.

Sadly, I think perhaps one of the folks who might have been able to help me (based on his post history/experience with similar equipment) passed away recently (Mike). He seemed like a great guy and a great contributor to this community. The sad part is not me not getting my questions answered (BTW). I went on a bit of a tangent yesterday looking him up and was very sad to see he passed away. I don't know if there is anyone at his ranch that still knows about this equipment. I feel like my best bet might be to find a very knowledgeable "old-timer" out there with a similar setup.

Things aren't catching fire just yet, so I'm digging deeper into the manuals and doing my best to self-educate. I need to evaluate the electrolyte solution for sure. I'm VERY concerned about the process of replacing the electrolytes (especially safely disposing of the spent materials). I'm actually so concerned about this that I can't help but wonder if my best path for the near-term is to disable all charging functions on both the XW inverters/charges and charge controllers and look for an adventurous DIY person who is willing to either buy/take these 40 NiFe batteries away.

I do have a few questions that aren't necessary specific to my setup/settings that you might be able to help me with. What is the best way for me to ascertain which devices (there are two of each XW6048 & the MPPTs) are handling the charging? Maybe I can chip away at one aspect at a time. I believe with the ComBox I can see if the XWs or the MPPTs are doing the charging in real-time.

Here is what I suspect. Whichever devices/settings are doing the charging when the grid is up are working because, even though it was a relatively short time, we still got a couple of hours of power from the batteries after the grid initially went down. After that, the generator was not set correctly (there was no sun at that point) and wasn't running long enough to get us back to the point where we could get another 2'ish hours of battery power. This tells me that (most likely) 1) the batteries need some TLC and, 2) the configuration of the AGS/charging is not right. We are definitely selling some energy back to the grid because I can see enough data to verify that (but, I totally agree, I don't want to waste energy charging crappy/unmaintained batteries).

Thanks again for your help! I also worry about resale of the home under the current setup. A swimming pool intimidates some potential buyers. I can only imagine how scary all of this would look to some folks who might otherwise love the property. I think we probably got a good deal on the property because most potential buyers were scared off by the 40 batteries in the basement. Unfortunately, the sellers misled us about multiple aspects of the system and then broke their promise to explain how everything worked once the closing occurred (because they were angry about the purchase price).

Thanks again (all assistance is greatly appreciated)!

Ed

EDIT: I think this might be the most relevant post for me on this forum. I think this is where I found mike95490 originally.

p.s. I always submit my post and it seems that the line breaks are twice at large once post the comment vs. when I'm composing my message. Is this normal behavior?

BB. · March 2023

Ed,

Probably your best place to start is with Dave:

Dave Angelini
"we go where power lines don't" Sierra Nevada mountain area
http://members.sti.net/offgridsolar/
E-mail offgridsolar@sti.net

He has the knowledge and experience to fully address your system... But this is his livelihood, so he does have to charge for his time.

However, he may be able to help you with locating help in your area (save air fares and time). He does have a good sized list of contacts he can look through.

Our forum is small enough that any post gets looked at by everyone here. Beginner simply describes your starting level of knowledge--It does not (I believe) limit any who may choose to read/respond.

It was sad when we lost Mike... And his loss even affected his wife/family directly regarding solar. There is nobody left (locally at least) that can help keep his NiFe system running reliably (off grid home?).

I do try to tell new members that we all are aging and trying to pass the knowledge of our systems on to those following is important. But even then, it is not always possible... And why I suggest that "retiring" into off grid life is does have its issues.

As far as I know, the electrolyte used in most NiFe systems is not a hazardous waste--But is caustic potash (KoH) which is a fertilizer. It "goes bad" through absorption of oxygen. And the dry powder can keep a long time--As long as it is in sealed containers (keep oxygen out). I do wonder a bit about how much nickle may be in the spent electrolyte solution. We are used to nickles in US change--But nickle is not a benign material and can cause contact dermatitis (Just a personal question--I have no idea if this is an issue or ).

Regarding Line Breaks... I have that "issue too". Basically with the Chrome Browser on a Chromebook, I have to hit "ENTER" twice for normal paragraph and space between paragraphs.

On Windows with FireFox, I have to only hit ENTER once, and I get the normal Para+Space... If I hit Enter Twice, I get "extra spaces" between paragraphs.... If I forget--I just edit the post and take out the extra line space.

To make sure you and I have a common starting point... Is this you inverter-charger / manual?

https://www.solarelectricsupply.com/media/sparsh/product_attachment/custom/upload/Schneider-Conext-XW-operation-guide_eng.pdf

-Bill

midwesteddie · March 2023

Bill,

Thanks! Yes, that is the correct manual.

Here is the manual for the MPPT 60/150.

https://solar.se.com/us/wp-content/uploads/sites/7/2021/10/Conext-MPPT-60-150-Installation-and-Owners-Guide_975-0400-01-01_ENG.pdf

Ed

EDIT: Here is some summary data from right now. It's a little cloudy but producing.

Need some help with settings after an extended grid outage on Friday

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