nife batterys??

[novaman]

I have a bunch of nife batterys and am looking for info on them, they are in a wood crate type box and have ared tag on them that says nickle cadium alkaline battery   would these be used for  windmill type aplication. thanks for any help. i have 20 of them and just wonder what the are for. they were in a barn when I bought a house a few years ago??

[Tritium]

Nife are nickle iron,  yours are wet cell Nickle Cadmium, They may still be fine as they are not temperature sensitive, nor charge level sensitive. they can be left in any state of charge without damage. They might need the alkaline solution changed out and a good charge. Google wet cell Ni-Cad for lots of information. They are VERY expensive new and nearly lifetime batteries. I priced a set a while back and here is what they told me:

A 48vdc 40cell 1020ah low rate KBL1020 system would cost about $50,000.
We currently have a special on some large in stock batteries and could
supply a long life 48vdc 24cell 3995ah STT2V4000 system for $35,000.
Ni-cads are great batteries but very few people want to spend the money
for them.

Look here for info as well http://www.sbsbattery.com/

Thurmond

[DanG]

They consume a vast amount of electricity with heat as the by product since their efficiency is around 70%, or, 20-40 percent make-up over previous discharge. Also the plates can suffer from spontaneous oxidation of the cadmium negative plates by atmospheric oxygen - a mineral oil layer on top of electrolyte keeps both the water in and the oxygen out, beware of cells stored dry. If you have excess power and wish a large heating element amidst the power room a known good set could be a good deal.

[independent]

Sorry Dan, that figure is wrong. I've tested my NiFe cells and I get a figure of around 83-85% measured with a Trimetric 2020. Isoutar found the same (over 80% efficiency) with his (tested independently from me, found out through correspondence). My cells are 2 years old. They probably lose efficiency over time, but I don't know when that is.
They are really nice cells, extremely well made from China--Changhong. Made for military applications and traction as I understand it. No smell, relatively benign, although not completely non-toxic (wouldn't be drinking that KOH!), draw down to zero no problems.
Also, there was a manufacturer from Europe called "Nife", they made NiCds in the end I think..

[isoutar]

Independent post about NiFe

Yours are ChangHong NiFe batteries too!   Where did you get yours?   I had to get mine custom made at the Chinese factory.    Is there a NA source?

Ian Soutar

[CraigCarmichael]

The efficiency depends considerably on the rate of charge and of discharge versus the internal resistance of the cells. To charge Ni-Fe's up quick, you may put in (eg) 1.7 volts, whereas you could charge it up slowly with (eg) 1.4 volts. The extra .3 volts for the fast rate is wasted energy.

Same goes for discharge. If you have a small load, the voltage might be (eg) 1.3 volts, but with a heavy load it might only supply (eg) 1.0 volts, again losing .3 volts.

So for a heavy, fast charged use:  1.0v (out) / 1.7v (in) = 58% efficiency - on top of that, the amp-hours available at a high rate no doubt drops as well.

On the other hand, for (eg) solar home with gradual charge and low loads:  1.3 v (out) / 1.4 v (in) = 93% efficiency.

But let's examine a few more numbers: Lead-acid's probably fare as badly if not worse with high loads. Their amp-hour specs are given for a very gradual c/20 (20 hour) discharge rate, and - from one typical "size 27" "deep cycle" battery spec - a "105 amp-hour" lead-acid will only last for 38 minutes at 75 amps, or 45 amp-hours. That's well under 50% efficiency without even considering the voltage drop or recharging it. (At 25 amps, it's up to 67 amp hours, and at 5 amps you get the whole 105 A-H.)

Of course you shouldn't try to draw much more than 50-60% of the charge out of a lead-acid if you want it to keep on working. As I mentioned recently, adding sodium sulfate will make it considerably more forgiving of deeper discharges and much longer lasting. For Ni-Fe, Ni-MH you can draw off 90% of the energy with no problems.

I'm not sure the self discharge of Ni-Fe is much different than Ni-Cd or some Ni-MH'es. Lead-acids are certainly not without self discharge either, but that's enough comparisons for me for today.

--Craig

[admin]

Big problem with NiFe and NiCad --

Good luck finding a modern PV charge controller or inverter/charger that even has a setting for *either* NiFe or NiCad.
Without such a setting, you will have problems.

ADMIN

[isoutar]

Odd chemistry battery ... NiMH, NIFe, NiCd etc.  how do you find a solar charger for them.

It turns out that most maximum power point or MPPT type controllers such as the Outback MX60 and many others have setting where you decide the exact charge voltage and equalize voltage as well as timing for a charge absorption etc.

I would highly recommend these types of controllers for unusual battery chemistries and have been using the Outback for 4 months on a nickel iron battery bank.   Such a controller is fully flexible and will work with any battery system, including those yet to be invented such as the Ni-Maganese battery that Craig is working on.

Ian