Dan, I have been living on Ni-Fe batteries for several years now and I have somewhat mixed feelings. I love them but I also dislike some aspects of them. First of all, as everyone mentions, they have a very low round-trip Wh efficiency, and secondly, they do use a lot of water. Otherwise, they are quite good. Iron Edison is great with tech support and they have the voltage parameters figured out really well. I believe that there are a lot of myths out there about Ni-Fe, but from what I've seen and heard, if you can afford them, if you can make sure to have an oversized PV array, and if you have time to top them off with distilled water every month (never skip a month!!!!!), they are a really great battery.
If you do use Ni-Fe, I have a few suggestions/tips... * First of all, never try hydro-caps with these batteries!!! I found mixed information on this one so I called them up and the owner of the Hydro-caps company claimed that they are compatible with Ni-Fe so I figured I'd give them a try. The Hydro-caps started to melt and they failed to release any of the pressure. This caused two of the batteries to explode. Thankfully I had two extra identical Ni-Fe batteries so I just switched them out as an experiment (and removed all the Hydro-caps) and my system is running fine. * Iron-Edison sells an "auto watering system" and a compatible "water cart." I highly recommend this accessory, but of course, you (or the customer) only fill the batteries while you or the customer is carefully monitoring it. You never leave it going to "keep them topped off. If you have this system installed then watering the batteries is so easy. It's a breeze. If you're filling these by hand then forget it... they would be terrible... * They also sell and recommend a deionizing filter that is supposedly good enough for purifying the water for the battery. This would cut the cost of the distilled water and since Iron Edison is the one holding the warranty, I have a fairly good level of confidence that it won't hurt the battery. If it did end up hurting the battery, it wouldn't void the warranty. * My batteries do get very cold (perhaps 10°F inside the electrolyte) and they don't seem to mind too much. Perhaps they do have a somewhat lower capacity. * Make sure they aren't undersized or else they'll struggle with the surge loads. * The PV array needs to be quite large. Make sure that the PV array can produce at least a C/6 at the nominal battery voltage, and C/5 or C/4 is better if the customer will be running much during the day. In other words, if you have a 500 Ah 48V bank you should make sure that the array is an absolute minimum of 4 kW (500 * 48 / 6 = 4,000). These batteries need a hard charge every now and then or else they start to act like they are going bad. If you take a battery that seems to be going bad and you give it a really good hard charge then they often come right back and there is nothing wrong with them. * I wouldn't use these on a grid-tied system. * I have always been skeptical about pre-packaged systems. Iron Edison seems like a good company but I still don't know if I like the pre-packaged idea. * After taking my previous points into consideration, if the customer is still leaning that way and they had the budget, I wouldn't hesitate to use a Ni-Fe, but on the other hand, most people would weigh the factors and decide that it's too much up-front investment, and/or too much maintenance. Many who are willing to do the maintenance don't have the funds, and many who have the funds wouldn't be okay with the maintenance. For the first case, Lead-Acid is definitely the way to go, and for the second case, LiFe-PO4 is better. That being said there are a few people who will weigh all the factors and still gladly go for the Ni-Fe because if you go install a Lithium battery tomorrow, my Ni-Fe battery will still most likely be alive and strong when your lithium battery goes out. I hope this helps a little! Thanks, Kienan Maxfield Solar maxfieldso...@hotmail.com<mailto:maxfieldso...@hotmail.com> (801) 477-0-SUN (477-0786) (801) 631-5584 (Cell) ________________________________ From: RE-wrenches <re-wrenches-boun...@lists.re-wrenches.org> on behalf of jerrysgarage01 <jerrysgarag...@gmail.com> Sent: Wednesday, November 21, 2018 8:30 PM To: RE-wrenches Subject: Re: [RE-wrenches] Ni-Fe update? Wrenches I have used Iron Edison Batteries and 12 volts is tough but l have had no issues at 48, you can set the high side voltage enough to work well. They are a very thirsty battery technology but may last for ever. Round trip efficiency is 70% at best so a larger array is required and the batteries don't like it to cold either. Jerry Sent from my Verizon, Samsung Galaxy smartphone -------- Original message -------- From: Ken Schaal <k...@commonwealthsolar.com> Date: 11/21/18 11:36 AM (GMT-08:00) To: RE-wrenches <re-wrenches@lists.re-wrenches.org> Subject: Re: [RE-wrenches] Ni-Fe update? Hey alexis. Any thoughts regarding these comments about Ni-fi batteries? Ur running them DC direct? Hope all is well. Ken On Wed, Nov 21, 2018, 2:25 PM David Katz <dk...@backwoodssolar.com<mailto:dk...@backwoodssolar.com> wrote: AEE Solar sold NiFe batteries from Russia in the late 1990s. They last a long time but were hard to use with inverters. A 12 volt pack has 10 cells. Each cell reaches full charge at 1.7 volts so the pack would be at 17 volts. that is 68 volts in a 48 volt pack. inverters turn off for over-voltage before that. When they are operating the cells are at 1.2 volts. The charge efficiency is about 60% when you look at watt hours in vs. watt hours out. They also use a lot of distilled water. I had a set that required watering every 3 weeks. I did not keep up with watering once and one of the cells exploded when the water level got below the plates. I would suggest L-ion batteries instead. David Katz On Wed, Nov 21, 2018 at 10:37 AM Ray <r...@solarray.com<mailto:r...@solarray.com>> wrote: Charge efficiency is really low, Charging parameters can be hard to get right, Voltage is not stable under heavy loads, and they are really expensive to boot. I've never sold them for these reasons, but I have replaced some sets that customers were unhappy with. They seem to work OK, only if there are no large surge loads, and the battery and array are sized large enough. Unfortunately because of the cost, folks seem to really under size them, which only exasperates the above issues. There's good reasons this old battery chemistry has not been widely adopted by the solar industry. It does have its place, and I understand the train industry uses it because A) they have cheap on grid charging available, so efficiency doesn't matter, and B) they have telecomm type loads with very little surge. Ray Walters Remote Solar 303 505-8760 On 11/21/18 10:55 AM, d...@foxfire-energy.com<mailto: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<http://www.Foxfire-Energy.com> _______________________________________________ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org<mailto: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<http://www.re-wrenches.org/etiquette.htm> Check out or update participant bios: www.members.re-wrenches.org<http://www.members.re-wrenches.org> _______________________________________________ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org<mailto: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<http://www.re-wrenches.org/etiquette.htm> Check out or update participant bios: www.members.re-wrenches.org<http://www.members.re-wrenches.org> _______________________________________________ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org<mailto: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<http://www.re-wrenches.org/etiquette.htm> Check out or update participant bios: www.members.re-wrenches.org<http://www.members.re-wrenches.org>
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