Hello everyone, sorry I'm late! I have a nickel iron battery bank but cannot find a suitable inverter.

[electrocuted]

I am disappointed with the state of the solar industry.
It should have gone without saying right from the start that solar installations ought to have an attached battery bank, otherwise power at night is coming from what is usually a fossil fuel powered grid. There's nothing green about that. And yet this technology has been a long time coming and still, several years after buying a nickel iron battery bank I cannot find any equipment which will actually work with it.
When I found out that home owners with solar panels were also subject to blackouts in daylight hours I was gobsmacked. It is hard to imagine what these electrical engineers were thinking rolling out a system which could not be disconnected from the grid when the technology for doing so is essentially a simple switch. Now I have read about grid tie hybrid inverters which will still leave users without power in spite of full sun and a battery bank. It' just laughable that anyone could think this is acceptable, and the excuses have nothing to do with technical limitations or physics. Solar power should not be this complicated, and twenty years into the 21st century reliable uninterruptible free power is something we should all take for granted.
I have a mountain of burnt out or otherwise malfunctioning solar related electronic equipment and have taken a great many batteries to the scrapper.
I have joined this forum to share what I have learned and learn from what others have shared.
Working with solar has always been about workarounds and so I will head over to the danger zone to elaborate on the issues of nickel iron with off the shelf inverters and solar controllers.

 

[sunshine_eggo]

And you brought such a positive attitude with you! awesome!

 

[Short_Shot]

"Essentially a simple switch".

This is coming, or at least on the list, but requires significant monitoring and network infrastructure to determine which users should be dropped to zero grid output, when, and how quickly to bring them back up.

As for batteries, that's a massive cost that most people don't need or care about as they're simply looking to reduce their bill or carbon footprint not eliminate it.

And batteries themselves are a subject of concern regarding carbon footprint so factor that in.

 

[electrocuted]

If there is a blackout on a sunny day, what exactly is difficult about supplying the house while disconnecting the grid?
I do not see what it has to do with monitoring or other users or network infrastructure. Essentially the problem is that the grid tie inverters are trying to synchronize with the grid, and wait for mains supply before inverting. The micro inverters do this also. An ordinary inverter however just inverts when you turn it on and could easily be connected to a house with a switch to flip supply from the grid to the inverter and another switch for the solar array. Surely we shouldn't need a 2nd inverter and manual switching to use our own solar power in this day and age.
Is it not fair for me to blame the electrical engineers who design grid tie inverters for this obvious problem?

I am here on diy solar forum because off the shelf equipment doesn't work for me. Looking around I can see it doesn't work for a lot of people.

 

[PVorBust]

ignoring the bits I don't agree with - what sort of NiFe cells do you have? I've always had an interest in NiFe, but not gone down that path.
Did you buy commercial cells or roll-your-own?

What exactly do you mean by:

I cannot find any equipment which will actually work with it.

Charging profile? unsuitable terminal voltage?

 

[electrocuted]

I have 20x500Ah.
There are no settings for NIFE in the solar controllers, and a 24 volt inverter will switch off both from over voltage while charging or when full and from low voltage cut-off on account of the large voltage drop when running low. A significant amount of the 500 Amp Hours is thus not available. They can't be fully charged and they can'be fullly discharged. To solve the issue easily I would need an inverter which can tolerate up to 36 Volts and also down at least as low as 18 Volts. I am hoping that somebody here might know of such a device.
I have started writing a post for the "danger zone" sub forum on this site where I explain my attempted workarounds and new ideas for getting my existing equipment to work.
I wasn't aware that anybody was making their own NIFE battery banks. I am interested in this though and would like to give it a go.

 

[Short_Shot]

If there is a blackout on a sunny day, what exactly is difficult about supplying the house while disconnecting the grid?
I do not see what it has to do with monitoring or other users or network infrastructure. Essentially the problem is that the grid tie inverters are trying to synchronize with the grid, and wait for mains supply before inverting. The micro inverters do this also. An ordinary inverter however just inverts when you turn it on and could easily be connected to a house with a switch to flip supply from the grid to the inverter and another switch for the solar array. Surely we shouldn't need a 2nd inverter and manual switching to use our own solar power in this day and age.
Is it not fair for me to blame the electrical engineers who design grid tie inverters for this obvious problem?

I am here on diy solar forum because off the shelf equipment doesn't work for me. Looking around I can see it doesn't work for a lot of people.

How many blackouts have you experienced in sunny days? I am aware that some areas may have to deal with this due to poor utilities but it's not likely to be a common issue.

That said, there are plenty of grid tied systems that use a battery backup and can continue to run with the power out. I'm extremely confused as to why you think this isn't a thing just because a few devices on the market work that way. They use a built in automatic cutoff exactly as you'd expect.


Regarding why you don't see the connection monitoring being relevant, it's because power outages on sunny days can be *caused* by excessive solar production. There is a such thing as too much power on a grid. Though it seems I missed the intent behind your statement not having much to do with that.

 

[Short_Shot]

I believe that until this grid monitoring system is in place it cannot become ubiquitous as you suggest it should be due to the inherent problems involved.

That said. I understand that grid tie and net metering are different things, and not all grid tie supplies the grid, but it's a major concern in widespread adoption.

I mean I could be wrong but I recall reading an article discussing it a while back.

 

[chrisski]

What is the advantage of a battery that works with nothing?

Nickel Iron must have some serious advantages to purchase not just one at 50 ah that works with nothing, but twenty of them.

 

[Mcgivor]

I have 20x500Ah.
There are no settings for NIFE in the solar controllers, and a 24 volt inverter will switch off both from over voltage while charging or when full and from low voltage cut-off on account of the large voltage drop when running low. A significant amount of the 500 Amp Hours is thus not available. They can't be fully charged and they can'be fullly discharged. To solve the issue easily I would need an inverter which can tolerate up to 36 Volts and also down at least as low as 18 Volts. I am hoping that somebody here might know of such a device.
I have started writing a post for the "danger zone" sub forum on this site where I explain my attempted workarounds and new ideas for getting my existing equipment to work.
I wasn't aware that anybody was making their own NIFE battery banks. I am interested in this though and would like to give it a go.

There is equipment that can work with NIFE battery banks, they have custom settings which allow for the large voltage swings, they do however tend to be more costly, furthermore there are inverters which can interact with the grid programmable to incorporate various functions including AC coupling.

This equipment falls into the professional grade category, not the low budget market, where equipment is tailored to the common arrangements using preset algorithms, which typically don't include uncommon battery chemistries such as NIFE.

Both my controllers, Morningstar and Schneider can be programmed for use with NIFE batteries, along with my inverters, Schneider, which are customizable, including grid interaction, though I don’t currently have grid connection.

In short there are solutions but expect to pay a little more than the common marketplace offerings, which are generally built to a price point for the most common battery chemistries.

 

[Mcgivor]

What is the advantage of a battery that works with nothing?

Nickel Iron must have some serious advantages to purchase not just one at 50 ah that works with nothing, but twenty of them.

NIFE are extremely robust, long lasting at the expense of being inefficient, compared to other chemistries, including LA, they can be refreshed with anelectrolyte change and last for decades. There is equipment which can be programmed to accommodate their requirements, see above, they never caught on which makes them a black sheep of sorts.

 

[toms]

NIFE are extremely robust, long lasting at the expense of being inefficient, compared to other chemistries, including LA, they can be refreshed with anelectrolyte change and last for decades. There is equipment which can be programmed to accommodate their requirements, see above, they never caught on which makes them a black sheep of sorts.

Speak to someone that has been using them for a long time before you leap in.

I’ve seen many people go from NiFe to LiFePO4. Never seen someone go the other way.

 

[OM617YOTA]

Is it not fair for me to blame the electrical engineers who design grid tie inverters for this obvious problem?

I don't think it is, either fair, or a problem. The consumer is the one calling the shots, and apparently most of them have decided that backup power in the case of an outage isn't worth the extra cost or hassle, which is why so few such systems are sold.

For those of us who value such things enough to invest the research and cost, there are plenty of options.

I'm not seeing the issue.

 

[Mcgivor]

Speak to someone that has been using them for a long time before you leap in.

I’ve seen many people go from NiFe to LiFePO4. Never seen someone go the other way.

My experience with NIFE is extensive in railway signaling applications, some had been in service for over 30 years with electrolyte replacement every 3 years, despite that they wouldn't be my first choice, they are too inefficient in my opinion. Current technology such as LiFePo4 is far superior, so I would agree, it would make little sense switching back to an outdated format.

 

[PVorBust]

(NiFe) ~ they are too inefficient in my opinion.

Efficiency comes in many flavours.
Currently I'm buying 270W ex-house panels for $10 each (a few years old, but still above rated spec.). At that price, I can easily add a few extra panels to an array to compensate for poor performance in another area. If roof space is part of your efficiency equation, this may not work out so well!
If space and weight are not a consideration, then NiFe may be a viable choice.
Lifespan of course is one of the greatest Pro's, but that may not tip the balance on a pure economic analysis.

 

[Zil]

I have a MorningStar solar controller. I can set custom charge parameters with a simple, free, computer link.
But. There are reasons nickel iron batteries are not used. Energy rich chemistries displaced them many decades ago.

 

[Bossrox]

I don't know why you can't find a charger for them. Most chargers these days have user custom settings I'd think you could surely set in a good parameter. As for inverters, I know from reading much on nife's, they have slow energy discharge which would very likely cause an inverter to shut down from those batts not able to meet a surge demand but with enough parallel banks, that could likely solve that. I saw a guy with nife's use a bank of super capacitors to absorb a surge so the nife's wouldn't dip to low, might be a solution but not cheap. I hope you find a work around, those nife's would be an expensive boat anchor if you can't make use of them.