Wrenches; I have run my house on 12 volt NiFe batteries for 3 years now. I was going to write a long essay, but Kienen beat me to it. It's an excellent analysis, I agree with each of his bullet points.
All I'll add is that the batteries charge with decent efficiency up to 80% SOC. To get that last 20%, they do require 1.65 volts per cell, which most standalone inverter / chargers won't do off a generator - they freak out at a bit above 15v and shut down. I've used 2 tactics to get that last 20% when using a generator, and I have experienced the same issue that Kienen mentioned -- they need to get a nice strong, charge cycle every so often or else they will behave like a heavily sulfated FLA, but of course the NiFes don't sulfate. 1) after charging to 80% SOC with the generator, both of my charge controllers (outback and midnite) have no problem being programmed to a 16.5v absorb cycle, I set absorb at 6 hours, on a sunny day that does the trick here. 2) If no long, sunny day available and you are forced to use a generator and charger that won't let you get to 16.5v, remove one cell from the series string, and charge the other 9 cells. Then put the one you removed back in the string, and remove one of the ones you discharged, and generator charge again. Then re-assemble back into a 10-cell string. I've only had to do this a couple times. In general, I'm happy with these batteries, and happy to never have to deal with sulfation again, and remember I have the worst case scenario here with a 12v bank, undersized because of the greater DOD capability of NiFes, a refrigerator that surges very hard, and a magnum inverter that goes wonky with big surges at low voltages. I would sell Iron Edison NiFes to a client...but unless they are a special sort of off-grid 12v person, I'd only do 48v because of the surge issue. Dan Fink Professor of Solar Energy Technology, Ecotech Institute IREC Certified Instructor™ for: ~ PV Installation Professional ~ Small Wind Installer Executive Director, Buckville Energy NABCEP Registered Continuing Education Providers™ NABCEP PV Associate 970.672.4342 On Wed, Nov 21, 2018 at 11:35 AM <d...@foxfire-energy.com> wrote: > Hi Guys, I have a potential customer inquiring about installing a pre > packaged Iron Edison system.. I recall hearing strange stories about Ni-Fe > batteries but don't recall the specifics. I have done a few searches with > mixed results.. And have friends advising I run like a Rabbit.. Thought I'd > run it by you folks for an update.. > Thanks, and Happy Turkey Day. > > db > > > Dan Brown > Foxfire Energy Corp. > Renewable Energy Systems > (802)-483-2564 > www.Foxfire-Energy.com > _______________________________________________ > List sponsored by Redwood Alliance > > List Address: RE-wrenches@lists.re-wrenches.org > > Change listserver email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: > http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out or update participant bios: > www.members.re-wrenches.org > >
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