# LiFePO4 battery bank - switchover complete



## 50ShadesOfDirt (Nov 11, 2018)

In an earlier thread, I had talked about planning for a switchover from FLA (lead-acid) batteries to LiFePO4 (lithium) batteries. Everything is now complete ... seems to be working well!

New battery bank:

two 12v x 300Ah Ampere Time sealed LiFePO4 (lithium) batteries, 60 lb's each, in series, for our 24V system.
get to use almost all of the 300Ah (the docs say I _can_ consume it all), for 2000+ cycles or thereabouts; by backing off of that by some amount, we might get correspondingly more cycles; 5 years or so by my math ...
no maintenance, whatsoever ... much space left over in my battery box

Former battery bank:

Had: four 6V x 468Ah Rolls-Surrette FLA batteries, 125 lb's or thereabout each, in series, for our 24V system; much maintenance required, battery acid (spills), etc.
Paid for 468Ah, but never really got to use more than 234Ah (FLA operating constraint) per cycle; should've gotten about 4 years out of them, but lasted about two years for us.
was about the largest FLA bank I could go without parallel battery banks, or moving to many 2V batteries (both at higher costs than the single bank above), due to our 24v inverter.
pretty sure they are sulphated or otherwise damaged, such that I wasn't getting more than 50Ah or so per cycle.
Lithium batteries are indeed the right stuff! I think this is the way of the future ...

Get to experiment on "desulphating" the older batteries, which gained weight from all the electricity pumped in over time ... hard to lift now! Will use a NOCO Genius 10 charger, which has a desulphate (bring back to life) battery charging function.


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## doc- (Jun 26, 2015)

Great!...You are now using a new tech that is only miserably environmentally unfriendly instead of old tech that is horrendously environmentally unfriendly ....What did your free electricity cost you to switch over, and what will it cost you again every 5 yrs? (Assuming the Chinese are still talking to us in 5 yrs and you can replace them when they poop out.)

Have you counted the added cost of extra large fire extinguishers to save the rest of your house when the new batteries spontaneously burst into flames and the fire can't be put out?

li fe po4 batteries fire hazard - Bing "
_"What should I do if my lithium battery catches on fire?
As such, for the most part you need to just let it burn itself out (it is good that the batteries are usually small). You can use a standard class ABC fire extinguisher to prevent the spread of the fire. Avoid using water on the lithium battery itself since the lithium and water can react violently. 2b."

" What are the disadvantages of FePO4 batteries?
Batteries are an inherently dirty business and LiFePO4 is the least dirty of anything currently on the market. The disadvantages of LiFePO4 batteries. If you think LiFePO4 is the gold at end of the battery rainbow, then this is the part where the fairy tale is busted. The most noticeable disadvantage is the cost.'"_

I hate being such a curmudgeon, but, kid,-- there just ain't no Santy Klaus,


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## 50ShadesOfDirt (Nov 11, 2018)

This thread drew some FUD ... I must have posted to the wrong community here ... no, the title _is_ "_alternative_ energy" ... hmmm.

I've been using lithium batteries for many years, and nothing has ever caught fire. In any case, my utilities shed is separate and away from the house ... as a firefighter, I designed many such safety factors into our homestead.

I took advantage of new technology to improve another area of our homestead ... I had hoped that my example would be one of "here's a case where it is working for this off-grid family". More examples of something having worked, and now working better, might help others on the HT forum?

Or is this some kind of argument about _on-grid_ and _off-grid_ ... depending on how one chooses, it becomes "us against them"? Interesting ...

I'll mark you down as "undecided" for now ...


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## Wellbuilt (Dec 25, 2020)

O cool I’m glad you are liking them . 
My buddy and I are working on a setof 280ah battery’s for his travel trailer . 
He has a 1500watt Samalex inverter charger
With a tracer mppt charge controller 
And a couple 200watt solar panels . 
I use out back equipment with 16 6 volt golf cart battery’s . 
I’m going into my third year with them and they are still looking good . 
I hope to get 5 /6 years out of them, I have a small system with 2 6v batters going on year 7


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## Alice In TX/MO (May 10, 2002)

Some folks are curmudgeons.


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## RJ2019 (Aug 27, 2019)

I'd be interested in knowing how the batteries perform in the long term.


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## 50ShadesOfDirt (Nov 11, 2018)

Performance in the long term ... that may have to be extrapolated, unless I can find some studies.

To date:
1.) much less space and weight (old fla=500lb's, new lithium=125lb's)
2.) 200Ah per cycle (the number we settled on using as a cycle), which should double the amount of such cycles we can get out of these 300Ah batteries. We risked sulphation of the old batteries if we got too near this number (and probably did).
3.) no maintenance, at all ... I'm looking at the fla distilled water, tools, masks & clothes, and such from the old fla, and figuring out what to do with all of it.

LiFePO4 is where we should've started ... with prices continuing to come down, I'm looking to replace car, tractor, and other such battery use on this homestead. Further out on the acreage, I'll need some remote power sources ...

Even the chicken coop, which has to support automatic doors, security cams ... egg turners ... (just kidding on that last one).


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## 50ShadesOfDirt (Nov 11, 2018)

Doc- did point out something I found to be truly applicable, which is ... what to do if SHTF, and "china won't sell me the next set of batteries".

I think the short-term answer is, every thing that we are doing per the S&EP forum ... the appliances go idle (more of a convenience, really), we move to pre-electric activities (burning wood for lots of tasks, pump water by hand, etc.) ... we aren't near 90%, but working to get there.

Long-term ... I can't hook up to the grid (assuming it is still running), as it is too far away for us, at ridiculous pricing. So, will need to figure out how to do things like run critical stuff directly off of solar panels, with no batteries in the middle. I'm rummaging through the notes, and sure enough, I haven't considered that ...

Maybe a water storage battery bank ... solar pumps it uphill, hydro gens electricity when water comes downhill. We'll "plug into a faucet" ...


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## dennisuello (Apr 19, 2021)

In the same boat here. Hooking up to the grid on my property would cost $20k to just run the HV wire and conduit. $20k will buy quite a bit of solar equipment and I would not be relying on power company for at least 10 years. LiFePo batteries should last at least 10 years, then there should be new/improved technology available to get more storage for less money. Going to have a propane generator backup, another backup option is a PTO generator for the tractor. There are quite a few things you can run off DC directly, bypassing the need for battery storage, or at least removing some of the load and extending the life of your battery pack.


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## Steve_S (Feb 25, 2015)

Power Co wanted $55,000 to bring power up here... NOT.
Original Solar system went in with 8x Rolls Surette S550's set in Series/Parallel for 24V/428AH/22kWh "Gross".
Net useable power was 11kWh or 214AH from that bank, Cost was $3200. Pain in the Keister with the monitoring, watering etc but still done and just didn't cut it.

Now switched to LiFePO4 (LFP). At present am running with 24V/910/23.2kWh and just completing final changes which will bring me to 1190AH/30.1kWh of stored energy. Using 3, 24V/280AH Packs & 1, 24V/350AH pack in parallel,

Battery Packs are all DIY. 
Current 910AH setup








2x 175AH at top &
2x 280AH at the bottom,
SmartBMS' controlling SoldState Contactors for each battery pack.








Above: 24V/175AH
These are being combined into a 24V/350AH pack with 2 cells in Parallel.









<- 24V/280AH









Below is a Case Diagram for a 24V 280AH 8S "Block Pack".
























*Example to build a DIY 24V/280AH Battery Assembly *
8x 280AH EVE Cells Grade-A Matched. $122 ea = $976 USD with welded studs.
- or -
8x 280AH EVE Cells Grade-A Bulk. $ 92 ea = $736 USD
1x 250A-300A SmartBMS varies, $200-$400 USD
1x Fuse per Battery $25 average
1x Casing/box - up to you - depends.

So DIY 24V/280AH : $976+$300(bms)+$25(fuse)+$100(casing) = $ 1401
Compare with Battleborn *12V 270 Ah* LiFePO4 Deep Cycle 8D Battery *$2,800.00*

Link to Shenzen Luyuan Tech, a Known Good Vendor/Supplier used by many of us at https://DIYSolarForum.com.
YW-3.2V-280AH, YW-3.2V-280AH direct from Shenzhen Luyuan Technology Co., Ltd in CN (alibaba.com)

ATTACHED is the* Luyuan Tech Basic LiFePO4 guide V1.0a.pdf *which explains in more detail the preparation and configuration details & requirements on how to assemble battery packs.

Hope this info helps, Good Luck.


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## Wellbuilt (Dec 25, 2020)

Nice system , I’m going to have to get serious about switching from lead acid battery’s when mine die . 
How are you guys getting thru inspections with home made Chinese battery’s .
I need every thing to be ul listed here , I don’t think my homeowners insurance would cover me for a house fire . Any thoughts ?


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## 50ShadesOfDirt (Nov 11, 2018)

A good question ... at what point does something "need" a UL listing? Why do we even care, except for "insurance" getting another reason to deny a claim? Building codes require "stamps" on wood; insurance requires "UL" listings, loans require "insurance" ... everywhere you look, you are told "you can't be self-reliant" anymore.

We build or assemble things ourselves, and try to avoid all the madness.

We do our homework on a purchase, by which point we've mostly ruled out the shady stuff. It takes time, but helps us avoid another kind of madness, which is bad manufacturing.


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## Steve_S (Feb 25, 2015)

UL, CSA, ETL etc are for commercially assembled/made products. DIY doesn't get there. Insurance Co's can be nuts, any excuse to not payout if something goes wrong, of course. There are reasonably prices Commercially made LFP Stackable packs by GYLL as well as others but you can easily drop another 50% on top of the DIY cost or more.

A LOT of people are DIYing battery banks and some pretty darn big ones to run serious power and I believe they are covered with insurance etc and some had some stupid rules for containment but not insane. Mostly it had to do with where the batteries were located, ie not inside the inhabited areas of the home, so in the garage, external building/shed etc...


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