# Replacement batteries for off-grid...



## Al Yaz (Jun 13, 2017)

Thought I would start a new thread and try to glean some information here as the day is coming where I will need new batteries. Ours are about ten years old and they are starting to get a bit tired. 

Anway, right now we have twelve 2v Davidson FLA batteries, hooked up in series for a 24v bank. They are 1065 a/hrs.

I have been reading a bit about newer FLA’s with carbon, and Lithiums. I don’t think I would go with nickel iron batteries, because of their initial high cost -even though they last a long time. I don’t see us being here in 30 years, so it’s probably FLA or Lithiums. I also don’t see gel or AGM’s as a good bang for the buck right now. I don’t mind watering FLA’s and our setup doesn’t allow for temperature fluctuations or freezing weather at the batteries.

So, if you guys were looking at new batteries and considering FLA’s or Lithiums (you want them to last at least ten years -maybe a bit longer if treated right) do you think the lithiums have enough positive qualities to spend the extra money? From what I am seeing, if a FLA bank costs me $7K, the lithium bank will cost me double. Guess my thoughts are that while lithiums will be / are the way to go, right now they are still too expensive to justify, when money is an issue...


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## Darren (May 10, 2002)

Are the nickel iron batteries the Edison type?


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## Al Yaz (Jun 13, 2017)

Darren said:


> Are the nickel iron batteries the Edison type?


Yes, those are the ones I was reading about / looking at.


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## Meinecke (Jun 30, 2017)

Keep an open eye on redox-flow batteries...Australia already has some good products out, so maybe they will show up soon here too...


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## Darren (May 10, 2002)

Al Yaz said:


> Yes, those are the ones I was reading about / looking at.


Are those set up so that the owner can replace the electrodes and the electrolyte? There was something odd about the life. It was long to begin with but it seemed like it could be extended.


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## Meinecke (Jun 30, 2017)

Yes...that's the ones...due to the aggressive Electrolyte, pumps are a wear out part...but so far a light on the battery issue horizon


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## Steve_S (Feb 25, 2015)

Your hardware is presently setup for FLA, can your charge controller make use of LiIon or other types ? If not, add in the cost of new controller... make a good excuse to upgrade to a new MPPT controller with extras... just sayin... Your comfortable with FLA and they are indeed cheaper than alternatives - I'm a fan of Rolls Surette (got a row of them  ) and you should get a reasonable 10+ years. In the meantime LiIon and LiIon Solid State are going up and Solid State has the most promise "at this time"... Energy Storage is the new Gold Rush and the rush is on and speeding up but you also know what that means... where will the chips land and at what price is anyones guess.

Take a look at your existing hardware and see what it is compatible with, or if there is upgrade firmware to enable features...

AGM/Gel batteries are usually used in Road Signs, remote sites with varied temps etc... The RV/Marine ones are tougher and better than automotive ones but they have issues too and pricey when you add it up. 

A few might bash me on this BUT not everyone wants the latest & greatest gizmo or doohickey. I remember $2000 Betamax machines do you ? Look at the people that have to have the latest iProduct and price matters not. Most people weigh the change purse and count the bills and decide what is good for them... Many people are still responsible with their cash, especially as we get older !

Fairly good over view "In English" with minimal tech babble.
http://theconversation.com/a-guide-to-deconstructing-the-battery-hype-cycle-79180


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## Al Yaz (Jun 13, 2017)

I am pretty sure my controllers (3 Midnite Solar Classics) and my Magnum inverter remote all have custom settings for battery set points. Interesting you mention the Rolls batteries though cause I have highlighted the Rolls 4KS21P’s or the Rolls 4KS25P’s as possible candidates. They should fit the bill and also fit within my battery enclosure footprint, which in my case is important. I have heard nothing but good things about Rolls/Surette. 

Ya I’m really leaning towards the FLA’s as they are proven and no real gamble, providing a person looks after them. I think I have a pretty good handle on how to treat FLA’s now so that’s a plus too.

Also funny you mention the Sony Betamax machines. After much research I was one of the idiots who bought one (Didn’t pay that much though) thinking it was where the industry was going... Ha!


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## Steve_S (Feb 25, 2015)

Yeah, kinda showed my age I suppose... I remember having to "program" in the 13 TV channels with those horrid tiny micro-switches - before menu driven software existed... LOL.

The trade off is "at the moment" is while LiIon will cost more up front & it being an evolving technology, it does offer much greater DOD (90% safe side) as opposed to FLA which you can't drain. Recharge time is faster on LiIon as well and of course no maintenance. 

Here is the pricing for LiIon from the supplier I got my solar equipment from - NOTE it's a Canadian Dealer, so 25% Currency difference to USD. https://www.solacity.com/product-category/batteries/lithium-ion/ But it's a point to compare.... 

Here is a fairly good article from RELiON battery co, worth a good look as well as the doc / paper at the end of the article. http://www.relionbattery.com/blog/7-facts-and-figures-comparing-lithium-ion-vs.-lead-acid-batteries

Ironically, there does not seem to be anyplace that you can plug in the info about an existing FLA setup like yours or mine and have it come up with what would be the equivalent in LiIon. Like your current system is 24v bank with 1065 a/hrs - what is the equivalent LiIon or alternate batteries. You would think there was a site that would show you something like that in an easy way... probably would increase sales IMO as the info is not easy to find and somewhat obscure in general. BUT Companies like RELiON has a number you can call and they can tell you the equivalent... not sure if I like that method of getting contacts.


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## Al Yaz (Jun 13, 2017)

Fwiw, Iron Edison told me that a 700 a/hr Lithium bank would be the equivalent in my case. I haven’t detailed what that really means, but I still see the cost, initially and even over the long term being more expensive with Lithiums. I’m sure the prices will come down eventually.


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## Steve_S (Feb 25, 2015)

Hmmm they wanna sell you 15K +/- worth of LiIon. Now you know why I went Rolls Surrette FLA and the other reason, they will outlive me in any case... At least you have a baseline to start working with to figure out what is best for you & yours.


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## chsdiyer (Feb 18, 2017)

Steve_S said:


> Solid State has the most promise "at this time"


Are solid state even in the horizon for an off grid situation. perhaps I'm wrong but solid state batteries have minuscule capacity when compared to what's needed for this application or any and I wouldn't see it getting there any time soon. Maybe cell phones some day. Am I wrong or are we talking about different solid state batteries?

Have you looked at the Tesla powerwall? They seem to be the best price for Lithium option and have the inverter built in.


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## Steve_S (Feb 25, 2015)

Solid State batteries have 5x the energy density (capacity) and have typically double the charge cycles as there are no electrolytes and because the membrane prevents the formation of Dendrites. Dendrites short out the batteries resulting in a fire - no different than laying a wrench across you car battery terminals, most unpleasant, you have likely seen the Youtube Videos and News about Lithium Exploders, Solid State prevents that altogether. You can actually, fold, spindle & mutilate without risk, other than maybe getting a good zap. 

In fact Toyota announced that their EV will use Solid State, Here's a reasonably good overview of what they are doing: https://www.extremetech.com/extreme...rs-new-solid-state-lithium-ion-battery-design

This is an area of extreme interest to myself and my Financial Wizard who is also a Greeny !

The Tesla Powerwall is not exactly good for off-grid - will do it but not designed for that, there are better existing solutions. Tesla is basically pulling a combo Howard Hughes (radically out there non-conformist and visionary) & Thomas Edison who ripped many ideas from a variety of inventors and used the US Patent system to lock them down, while crushing potential competitors... which he tried in vain to do to Nicola Tesla in the great " AC vs DC " war and more.... one of many well documented yet quietly ignored things he did...


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## chsdiyer (Feb 18, 2017)

Ok, same battery technology I was thinking about. It is cool/impressive, but I've had no luck finding a battery greater than 1mAh in capacity. That company was apparently bought out by apple and no longer supplies to the general public. If Toyota can get it to power a car in the next 5 years i'll be impressed. I've been doing energy harvesting research for several years now so those batteries appealed to me for a number of reasons. In that world I always come across companies marketing their technology as if it's on the market today yet years later, you still can't get them to answer the phone or an email. There's tons of marketing and publications done for energy harvesters but you can see how many devices are powered by them right? Not saying solid state batteries wont get there though.

What's the limitations on the powerwall? I don't know how they sell them so cheap if they do pack a 6kW inverter and 14kWh lithium ion battery. What would you suggest as a better alternative? I've looked for other lithium ion batteries but frankly the cost is a non starter. The LG system isn't bad, but it's more than a Tesla and you can only put two in parallel I believe. I did enjoy the Murdoch Mysteries episode where they did the old AC/DC battle.


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