Custom inverter / charge controller settings for Nickel Iron batteries

mike95490

When I was searching gear, the XW handled the needed voltage range - barely

Blayd

As an update:  I did hear from the Chinese factory rep.  I got the factory spec. sheets which differ somewhat from the two American distributors as being a lot more conservative on durability.  No pricing for factory direct. It seems like they desire large projects/new distributors. 

Given the current cost of roughly 4 times the Trojan L16 RE B 6vdc equivelents, as well as the wide voltage swings the current equipment would be facing, and last but not least the increased de-ionized/distilled water appetite the NiFe jugs require, it does not make finacial sense for me to invest in NiFe jugs at this juncture.

I did a massive upgrade on solar in 2016 so that I was not cycling my current Pb/acid L16's during the daytime which should gain me a couple years of battery life with the current configuration, and by increasing storage times two may give me 10 years service on a new set of eight L16 RE B's which will cost around $3000 usd and have the reduced specific gravity level to handle the extreme heat for area.

Hopefully in ten years time other options will be available which will be even better that what even current leading edge offers.  We shall see.

Dave Angelini

Good decision! Not even going there with the drop in efficiency from LA.

Blayd

Too bad the Edison batteries are no longer made.  In my research I discovered that back in the 1980's that one of a few work forklifts that I operated had a 12vdc Edison battery. It outlasted it lead acid companions by far with massive use and abuse.

If they were still available new, and priced right I would consider them.  I dont think it was watered much either.  Upon reflection, it probably never got charged enough to gas.

midijeep

mike95490 said:

With NiFe, you cannot use any state of charge meter, the battery voltage is way too variable. 
 If all you can manage is 1.66Vper cell, then, that's all you can do.   My inverter (xw-6048) can only charge up to 64V, but it does not fault until 67.5V  So, my solar charge controllers get the daily voltage up, and I have a couple hours of absorb on them before dropping back to float.  Winter (cloudy weather) I'm much lower in the voltage curve and can only charge to 64v until the sun returns. Then the battery sucks power from the PV for hours before it gets to absorb.

Does your inverter automatically ramp up the daily voltage or do you manually have to increase the charging rate during the day?
I have not found a setting for the Sunny Island to do thsi.  It seems to set on Float and the SOC needs to drop below 80% before a boost charge is automatically applied.  Wondering if anyone has their Sunny Island to increase volatage during the day and return to float at night?

Dave Angelini

The inverter does not charge anything ! It only discharges batteries. The charger in an Inverter/charger can charge.
Mike is saying that above 64V,  the XW inverter will start to shut down to protect itself and will drop ac output at 67.5 V.

mike95490

Actually, when charging from the generator, the big XW inverters also act as high amp chargers, (inverter/charger) but will only charge to 64V (max limit for lead acid batteries)  When sun is shining, the solar charge controllers can get above 64V

midijeep

Question about boost charging for the 48v battery bank of NiFe. 
I don't think my set voltage for boost charging is high enough to completely charge the NiFe battery bank 38 cells  at 1.2v each. 
Right now the SMA Sunny Island 6048 is defaulted to 1.65v for the boost charge but I can go up to 1.8v per cell.  If I change this setting to 1.8v, do you think this charging voltage would harm the battery bank or individual cells? How long would I need to do this?  The SI right now is defaulted to 300 minutes.

EQ charge I can go up to 1.8v
Float I can go to 1.60v
Full charging I can go up to 1.8

mike95490

It's very hard to hurt NiFe batteries,  IF you keep water in them and don't let them heat up.   If you don't have enough hours for a gentle charge, increase the charge voltage till you are getting the batteries charged enough.  But stop if the batteries start to get warm.