Compare Nickel-Iron Edison Batteries and Chinese Ni-Fe Cells

softdown · November 2016

I don't find much comfort in that battery cable...their customer is trying to show off?

Image: https://us.v-cdn.net/6024911/uploads/editor/2a/gkyg037kui6u.jpeg

mike95490 · November 2016

With our Nickel Iron batteries, you can discharge up to 80% of the total capacity without any damage the cell or its future capacity. With a lead acid battery, it's recommended to use only 20-30% of the total battery capacity to get 5 years of life.

You can USE 80% of the capacity (according to them) But the voltage range from Full to Empty, is so large, that many inverters will start to shut off from under-voltage before you get to -80%

softdown · November 2016

mike95490 said:

With our Nickel Iron batteries, you can discharge up to 80% of the total capacity without any damage the cell or its future capacity. With a lead acid battery, it's recommended to use only 20-30% of the total battery capacity to get 5 years of life.
You can USE 80% of the capacity (according to them) But the voltage range from Full to Empty, is so large, that many inverters will start to shut off from under-voltage before you get to -80%

Makes sense....their web site did not install confidence that they are battery experts. More like salespeople really.

What do you think of the chart showing the very strong correlation between water consumption and temperature?

Would you do NiFe again? I like almost everything but the price...

Is it possible to find much better prices anywhere?

TGC · April 2017

Hi Mike,
Just bought 40x500Ah from CiYi (very good experience buying direct) - still fingers crossed I made the right choice including capacity, ...maybe I should have gone for 800, but the good thing about NiFe is that I SHOULD be able to add more in parallel if needed.
In any case my questions are:
Do you have an update on capacity drop since you bought them ? (that would be 6y ago, right?)
When you say they are water hungry - how much exactly say per cell per month? and have you found any tricks to reduce that?
Thanks

TGC · April 2017

sorry @mike95490... previous post for fya.

mike95490 · April 2017

Lower charge voltages = less water use, but less capacity. I go through about 5 gallons in 2 weeks.. (I batch refill about 1/3 of my cells at a time, then 2 weeks later, another 1/3 of them - it's a lot of work, dribbling 1/2 gallon into each cell)
No noticeable drop, they actually seem to be holding up overnight even better than when new, or I'm getting more dialed in on the charging of them.
Adding more in parallel would be painful - come time to water all of them !!

TGC · April 2017

thanks for that - very true re watering large numbers if I put more in parallel...! Maybe I should have gone 800Ah. Oh well.
20 litres every two weeks !!! Gah. Not looking fwd to that. Need to think about an industrial distilled water production. I don;t think rainwater would do.... too much organic residues from the tanks.

Dave Angelini · April 2017

Filter the rainwater, maintain the tanks! Have it tested. I have had two sets of batteries in over 20 years offgrid.

TGC · May 2017

Thanks Dave, very interesting. Do you mean that you use the tank water (properly maintained) in the batteries directly? Correct? Lead acid?

Dave Angelini · May 2017

No Sir! I use a Britta filter from Costco before the lead acid battery.

TGC · June 2017

Guys, esp @mike95490, I need advice. Newly installed 500ah 48V NiFe, and, I'm trying to cycle them as you should for new ones, but even after 4/5 cycles they are still not at full capacity
a) if I put a 2kw load, the voltage drops to 36V after about 3.5hrs. After that I still can use a 1Kw load for another 4hrs or so, but I can't draw more than at any point 2KW without heavy voltage drop. The missus not going to be happy if the 2.4Kw hot water doesn't work....
b) when it gets to low voltage, as soon as I take the load off then voltage bounces back to 46V. You can imagine the inverter cycling every 20sec low battery cutout > battteries recover instantly > inverter starts again > voltage drops instantly > low battery cutout ...
c) it looks like they have plateaued at 1Kwh out of 24kNwh, but I can't cycle them more?
d) What charging setting are you using Mike? At the moment I'm at 62V absorption which gets me about 50/60A into them, and the charge current drops to float in about 4hrs, so I get 12Kwh out of them, which is consistent with the discharge, but not enough!
e) Shoould I try a slower charge? I can current limit (Schneider 8548), but if I put the absorb voltage at say 60 or lower, it might take longer?
f) Interested to know what charge setting you use @mike95490

Thanks !!!

(PS, measured voltage on each cell, they all behave the same, so there isn't a dud one... as I hoped)

TGC · June 2017

Sorry, meant " I can't current lmit..."

littleharbor2 · June 2017

TGC said:

Sorry, meant " I can't current lmit..."

You can go to that post and edit it. Click on the gear at the top right corner of the comment window.

Estragon · June 2017

I don't know much about these batteries, but I don't think they handle high charge/discharge rates well. C/10 might be pushing it for these.

Assuming you are off grid, I would suggest getting a gas water heater to keep the missus happy, and maybe use the electric one as an opportunity load to preheat water ahead of the gas unit. As an opportunity load, the water heater would use solar generation that would otherwise be lost after battery charging.

Heating stuff off grid with pv except as an opportunity load generally isn't viable irrespective of battery type.

TGC · June 2017

Thanks for the tip @littleharbor2!

Lumisol · June 2017

Just a quick question. Are the batteries being compared comparable in price? ie. in the same price range?

mike95490 · June 2017

I run 1.6V per cell for absorb, and generally absorb for 2 hours.
My overnight load is about 4kwh
here's a chart of my low and high voltages (cloudy day, tricked the controllers into 3 absorb cycles) 67.5 - 53.5V just before dawn
Remember, NiFe is very high internal resistance, so you need about 2x the ah that a lead acid would be designed for, ( a 400ah lead acid bank can be replaced with a 800ah NiFe bank)

Compare Nickel-Iron Edison Batteries and Chinese Ni-Fe Cells

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