LiFePO4 - The future for off-grid battery banks?

[Old_Man]

So I'm comparing the cost of AGM deep cycle batteries with LiFePO4 batteries, and it seems that LiFePO4 will win out.

Hear me out...

Goal - Provide 1 kW of power.

Assuming 80% DoD for LiFePO4 and 20%DoD for AGM (Which will give us approximately 5 years for each type of battery), we will need:

x24 3.2V, 16AH of Headway LiFePO4 batteries for a 12.8V, 96AH pack (1.28kW) and

x2 12V, 255AH, Concorde AGM Groupe 8D batteries for 12V, 510AH pack (6.12 kW).

since 80% DoD of 1.28 kW = 1.0 kW and
20% DoD of 6.12 kW = 1.2 kW

Price for x2 Groupe 8D Concorde batteries ~ $1,200
Price for x24 Headway LiFePO4 batteries ~ $600

.. not to mention x24 LiFePO4 batteries only weighs about 30lbs.

I guess the price of the Battery Management System for the LiFePO4 cells and the complexity of the system far exceeds that of the AGM batteries for now. Perhaps the technology is still immature.

Are there any technical barriers from preventing the use of LiFePO4 batteries as solar battery banks? Maybe the discharge rate (100A)?

None, if you have a good MPPT controller.

[travissand]

And Bitcoin mining sure puts an interesting twist on how we'll use electricity in the future. Considering that a factory with a huge need for electricity in an overpriced area but let's say they buy the rights to an abundance of free energy in a remote part of the world they can instead of transmitting that power use it to mine Bitcoin to buy the electricity they need where they need it. It's an interesting concept.

[Ampster]

I haven't done the economics yet....

I then expect the next set of batteries to be much more expensive to the POCO's who will then pass on that cost to their customers. If you look at what other manufacturers have done in the past to latch onto a market I expect the battery manufacturers to do the same or they will lose investors if the profits drop.

Yes, we are in an inflationary spiral including the cost of fuel. I agree rates will probably go up for many reasons. I have done the economics and agree with long time poster, Jflorey, that Lithium storage is long term more economical than FLA.

In California the market is deregulated. Private investor groups are building battery facilities and selling into the spot market or getting paid for providing ressource availability. The projects have been more competitive than gas fired peakers.

[SunEagle]

Economics should drive most rational decision making. Scale does favor the larger facilities, but as demonstrated above, the economics are still there at small scale for those with a long term view. I don't know of any examples of Li manufacturers almost giving away their products. Do you?

I haven't done the economics yet but I will bet some POCO's have gotten their large Li battery systems for maybe cost or lower otherwise you would see a rise in electric rates to cover that expense.

I then expect the next set of batteries to be much more expensive to the POCO's who will then pass on that cost to their customers. If you look at what other manufacturers have done in the past to latch onto a market I expect the battery manufacturers to do the same or they will lose investors if the profits drop.

[littleharbor2]

I figured I'd check this against some available batteries out there.

EG4 LFP: $1500 for 5kwhr, 4kwhr usable: $375/kwhr
-Lifetime ~5000 cycles, cost per lifetime kwhr $0.08

Costco T105: $130 for 1.3kwhr, .6kwhr usable: $216/kwhr
-Lifetime ~500 cycles, cost per lifetime kwhr $0.43

Rolls S6 L16: $395 2.6kwhr 1.3kwhr usable: $303/kwhr
-Lifetime ~1900 cycles, cost per lifetime kwhr $0.16

I built my LFP 11.5 kwh battery for about $1,950.00 Quality Eve cells from a very reputable dealer (shipped from Houston)
10 kwh usable $195 per kwh
5000 cycles cost per kwh 0.04

[jflorey2]

LFP battery costs have certainly dropped but don't think you can put EG4 in the same tier as Rolls.

Agreed - which is why I included Costco T105's as a better comparison against a bottom-tier LFP battery.

Battleborn, Renogy, Discover, SimpliPhi and a few other LFP batteries are strangely expensive. For a better comparison you could look at Pylontech which have been doing very well in tests. Now that they have gone to 16S they are much easier to use as well. So for those:

Pylontech US3000C: $1757 3.5kwhr 2.8kwhr usable: $627/kwhr
-Lifetime 4000 cycles, cost per lifetime kwhr $0.15

[Ampster]

Well I feel the main reason for the POCO's using Li chemistry is because the Li battery manufacturers were trying to get a larger share of the market. They almost gave away the first set knowing that they can increase their charge for the next set the POCO has to purchase.

But that has really nothing to do with a homeowner going with Li chemistry.

Economics should drive most rational decision making. Scale does favor the larger facilities, but as demonstrated above, the economics are still there at small scale for those with a long term view. I don't know of any examples of Li manufacturers almost giving away their products. Do you?

[SunEagle]

That has been my opinion for some time. Glad to see you have an open mind. Also glad to see this forum is open to current realities. There is a reason why commercial energy storage has been using Lithium chemistry.

Well I feel the main reason for the POCO's using Li chemistry is because the Li battery manufacturers were trying to get a larger share of the market. They almost gave away the first set knowing that they can increase their charge for the next set the POCO has to purchase.

But that has really nothing to do with a homeowner going with Li chemistry.

[solardreamer]

I figured I'd check this against some available batteries out there.

EG4 LFP: $1500 for 5kwhr, 4kwhr usable: $375/kwhr
-Lifetime ~5000 cycles, cost per lifetime kwhr $0.08

Costco T105: $130 for 1.3kwhr, .6kwhr usable: $216/kwhr
-Lifetime ~500 cycles, cost per lifetime kwhr $0.43

Rolls S6 L16: $395 2.6kwhr 1.3kwhr usable: $303/kwhr
-Lifetime ~1900 cycles, cost per lifetime kwhr $0.16

LFP battery costs have certainly dropped but don't think you can put EG4 in the same tier as Rolls. It would be more appropriate to compare Battleborn with Rolls. Battleborn LFP battery prices are much higher than EG4 and other similar tier brands (e.g. SOK, etc.).

[Ampster]

Well I guess FLA is no longer cost effective compared to Li chemistry batteries. Good to know. Thanks for the work

That has been my opinion for some time. Glad to see you have an open mind. Also glad to see this forum is open to current realities. There is a reason why commercial energy storage has been using Lithium chemistry.

[SunEagle]

I figured I'd check this against some available batteries out there.

EG4 LFP: $1500 for 5kwhr, 4kwhr usable: $375/kwhr
-Lifetime ~5000 cycles, cost per lifetime kwhr $0.08

Costco T105: $130 for 1.3kwhr, .6kwhr usable: $216/kwhr
-Lifetime ~500 cycles, cost per lifetime kwhr $0.43

Rolls S6 L16: $395 2.6kwhr 1.3kwhr usable: $303/kwhr
-Lifetime ~1900 cycles, cost per lifetime kwhr $0.16

Well I guess FLA is no longer cost effective compared to Li chemistry batteries. Good to know. Thanks for the work

[jflorey2]

The last time I compared them the Li was still much more expensive for the kWh it could produce in it's life then a quality FLA battery.

I figured I'd check this against some available batteries out there.

EG4 LFP: $1500 for 5kwhr, 4kwhr usable: $375/kwhr
-Lifetime ~5000 cycles, cost per lifetime kwhr $0.08

Costco T105: $130 for 1.3kwhr, .6kwhr usable: $216/kwhr
-Lifetime ~500 cycles, cost per lifetime kwhr $0.43

Rolls S6 L16: $395 2.6kwhr 1.3kwhr usable: $303/kwhr
-Lifetime ~1900 cycles, cost per lifetime kwhr $0.16

[travissand]

IMO any battery chemistry that includes Lithium will last longer then FLA type. What I have said in the past and repeat now is you have to weigh in the cost of Li chemistry against FLA type to see which is more cost affective for you. The last time I compared them the Li was still much more expensive for the kWh it could produce in it's life then a quality FLA battery.

As Li chemistry batteries improve I believe the cost per kWh will come down and they will be very competitive to FLA type.

The cost per kwh fully depends on your ability to find the deal. My cost was unheard of cheap. I bought 700kwh and more but you can get brand new cells straight from China for a dang good deal which makes fla a thing of the past.

[SunEagle]

Thanks for that update, that's completely awesome. There's still so many people out there who think this chemistry isn't proven. My LifePO4 batteries are also 12 years old and still holding 96% of their original rating. These things are truly a dream compared to the other chemistries.

IMO any battery chemistry that includes Lithium will last longer then FLA type. What I have said in the past and repeat now is you have to weigh in the cost of Li chemistry against FLA type to see which is more cost affective for you. The last time I compared them the Li was still much more expensive for the kWh it could produce in it's life then a quality FLA battery.

As Li chemistry batteries improve I believe the cost per kWh will come down and they will be very competitive to FLA type.

[travissand]

Thanks for that update, that's completely awesome. There's still so many people out there who think this chemistry isn't proven. My LifePO4 batteries are also 12 years old and still holding 96% of their original rating. These things are truly a dream compared to the other chemistries.