NiFe Battery Customer Testimonials
Squishing the Myths:
We are in partnership with a company with sixty years manufacturing experience for the Military, so we don't sell inferior batteries. The depth of discharge (DOD) efficiency of NiFe batteries is over 80%. We hope the comments below clears some of the myths and provides a little more information on the use of NiFe batteries.
If your delivery time is not critical, we can save on freight cost by combining orders or by shipping directly to your nearest port !
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Please Note: We receive many Enquires regarding NiFe batteries Failing to basic 1.2VDC each after only a few Years !
Commonly for almost all Battery Cell Failures are Caused by either Over Discharging &/or Under-Charging or lack of Liquid Maintenance/Neglect, usually in that order.
This is the Time that I'll informed people sell there NiFe Batteries, for Lithium usually as they are Plug & Play.
Instead the Customer should have been told, "They simply need to Replace the Electrolyte of Clean & Service any Bad Cells".
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1) NSW, AUSTRALIA: We have sold banks of 40 cells of 1200Ah NiFe batteries (57.4kW) and our Customers have been testing the batteries for many Years now. Yes, we found the bigger batteries are more economical.
Regarding the price difference with other battery chemistries, we should take into account that the DOD (depth of Discharge) of NiFe is much deeper for the same life time, so you could use a smaller kWh for the same useful kWh. Not to mention the expected lifetime that is in the order of twice of flooded lead acid.
Regarding the charging efficiencies, please bear in mind that the 50% charging efficiency is only for the last 20% of the capacity. Up to 50-60%, the charging efficiency is pretty much 90-95%, decreasing as we approach 80%. The other advantage of not topping the batteries up till 100%, if that the electrolyte loss is then very minimal. We have been running our batteries for a few months now and had never to top up the electrolyte. We will be testing overcharging them during the hot summer months.
Regarding the self discharge, our batteries are getting less than 1% self discharge per day. For cycle use, this is completely irrelevant. We will be conducting more self discharge test in the time ahead.
A big reason to use NiFe batteries is that they can be overcharged (you need to top up the electrolyte a bit more often if heavily discharged) and you can completely discharge them without taking a big penalty in their life time. But, the main reason to use them, is the environment, the components of NiFe batteries are harmless for the environment and even the used electrolyte (recommended to change the electrolyte every 7 years), you could dilute it and use it in your garden to bring up the soil PH if needed.
Unfortunately, the internet is full of myths from people who have never used these batteries. These batteries (like all other batteries), are not for all people in all situations, but we can use their strength for renewable energy storage in stationary applications.
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2) Victoria, Australia: Installed over 7 years and my battery bank (1000ah x 48volt) is still performing exceptionally well.
I have a second battery bank at a remote property, I have (400ah x 12volt) that is the same age.
My house is fully electric (except solar hot water) and runs off our battery bank daily. In seven years I have topped the battery bank electrolyte up twice. It will be due for another top up in around six months.
I do not understand why self discharge is a key point in discussions. In regular use, self-discharge is a non issue (for most types of batteries).
Price is also another key topic. Simply remember that you will replace all other types of battery banks and their price will increase over time.
Nickel Iron batteries do not wear out, the electrolyte needs replacing eventual, usually you will get between 8~12 years life out of this electrolyte (depending on how hard you work these batteries) and this can be done over and over again ! The cost to replace the electrolyte is around 5~7% the initial cost of the battery bank, larger battery banks use more electrolyte.
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3) I personally use an Outback MX60. It is generally not the charge controller that limits the use of Nickel Iron Batteries, it is the inverter.
As a NiFe has a working range of between 0.9volts and 1.7 volts per cell, most inverters on the market do not have the working range to utilise the benefits of these batteries.
I have my Selectronic inverter set at 100% DOD. Just to clarify 100% is the lowest setting on my inverter which is 39.6 volts (48volt battery bank). It is not 100% of the battery.
I have my bank charge up to 58 volts (1.45volts per cell). I know I get a lot of questions about why don't I charge up higher but please lets cover this later.
I have had installers look at my system and tell me you cannot do this or you will destroy your batteries. I have had this setting on my inverter since it was installed, 7 years, and they are still working.
We worked with the installer to get the most we could out of our system. As with most installers they do not understanding how these batteries work, the installer set the inverter to what he thought, and I played with the settings over a period of time to work out how I could get them most out of my batteries.
Nickel Iron batteries in theory do not wear out. The electrolyte protects the internals of the battery. You will get some build up of carbon at the bottom of the battery which is absorbed through the electrolyte, eventually the plastic casing will become brittle and I suspect crack but this will depend on how much they are exposed to sunlight.
I have not replaced my electrolyte. It is now just over 7 years old. It will cost less than 7% the initial cost of the battery to currently replace the electrolyte. You can add cells to a NiFe battery at anytime without any damage or problems. You can increase the voltage or the amp hrs or both at the same time.
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4) USA: In most cases, you will not need to replace the electrolyte before 10 years not 7 years depending on how hard you want to work them.
I would have thought that 7% to renew a battery back to obtain another 10 years is quite reasonable and doing this over and over until the battery casing fails is fairly inexpensive.
You are correct, charge efficiency does diminish as you charge to full as it does with most batteries that I am aware of, hence the reason why I charge to 1.45.
I am not trying to fully charge the batteries as they provide me with more than ample power daily set at 1.45.
I am in a rain catchment area and we get a lot of cloud and rainfall so I utilise the most of what sun we get.
39.6 volts is what my inverter allows me to discharge to. If the inverter allowed me to discharge to 38volts I would set it at that setting.
Some customers who use a different brand inverter can discharges to 38volts and are able to utilise the stored power without damage to the battery.
Based on information I received from some installers, the price of our NiFe batteries are comparable to good quality lead acid batteries (I have not confirmed this as I did not go around pricing other battery types) but if this is the case, then the ongoing cost of replacing the electrolyte every 10 years seems reasonable to me.
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5) Australia: I've had some experience with NiFe cells. This was a large back-up power system on a major road bridge. The system was installed circa 1977 and consisted of individual wet NiFe cells in series. Total operating voltage was 60 VDC.
After 25 years the cells were considered by engineers (I'm an electrician, not an engineer) to be at the end of their life and were replaced circa 2003. The inverters and chargers were also replaced, and the new system operates at 48V (simply because it was cheaper to obtain 48V equipment and, more importantly, 48V replacements would be easier to obtain in a hurry if something fails).
There were no real hassles with them and very few cell failures until the last couple of years when the failure rate increased (hence the replacement). I am told (I didn't work on the original installation - not old enough to have done that!) that the cells were poorly maintained through at least part of their life and that by 1985 the system was in an overall state of disrepair due to essentially no maintenance having been done. This is when a new operator took over maintenance etc and after that the maintenance was to a very high standard with monthly electrolyte level and system operation (full load) checks being done consistently.
I can't be certain, but I'd assume that the cells may have dried out to a considerable extent prior to 1985 - but if they did then they survived another 18 years with proper maintenance.
Also notable is that the bridge itself has a lot of heavy traffic (trucks etc) using it and noticeably vibrates. You can feel the vibration through your feet just standing on it at times (all perfectly safe and nothing to worry about according to structural engineers - it's a major bridge with regular structural inspections etc). So the NiFe cells were subject to constant vibration at least during business hours Monday to Friday when traffic is heavy.
The key reason for using NiFe in this installation is life span. There are 6 completely separate back-up power systems on the bridge at different locations, and the only way to get any equipment up there is to either carry it on the walkways (750 metres from the shore to the furthest away batteries) or to close an outside lane on the bridge and park a vehicle in it with the equipment. Closing lanes has to be done at night when there isn't much traffic and needs several people plus an assortment of trucks, road signs etc to do it so it costs a fortune each and every time it's done. Hence the cost of installing the batteries is high and life span is a major criteria. That plus it's deemed to be critical infrastructure - obviously they want to minimise the overall cost but reliability is the most important criteria of all. NiFe cells "tick all the boxes" in this situation. They're robust and the overall cost ends up lower simply due to the extended life span.
The new batteries are now 10 years old and no known problems have arisen. That said, due to the critical nature of the installation a diesel generator was installed a few years ago as a second back-up power supply. There are also two completely separate feeds from the grid, each capable of running the entire installation. So in total it's mains power x2, batteries and a diesel generator, so 4 power sources in total.
As for how efficient they are, I have no idea to be honest as it's not something that anyone was even slightly concerned about. Reliability was the key, and NiFe cells were used for this reason.
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