LiFePO4 - The future for off-grid battery banks?

[Fatawan]

Hi,

Has anyone run across an inverter/charger designed to charge lifepo4 batteries?

Thanks,
Zak

Yes--no need to custom build one

http://www.victronenergy.com/upload/documents/Datasheet%20-%20Quattro%203kVA%20-%2010kVA%20-%20rev%2012%20-%20EN.pdf

http://www.victronenergy.com/upload/documents/Datasheet_Lithium_ion_rev03_EN_web.pdf

[russ]

Before anyone gets too excited about the LifEPO4 batteries they might want to read Mike's (another moderator) posts about his set.

[Sunking]

Before anyone gets too excited about the LifEPO4 batteries they might want to read Mike's (another moderator) posts about his set.

He does not have LiFePo4 (Lithium Iron Phosphate). He has NiFe I believe.

[Sunny Solar]

Russ dont know where you got your info but Mikes batteries are Ni Fe. He has many posts talking about them .

[Sunny Solar]

As INETDOG has pointed out you can buy a 12,24,48,96,and 144v Life PO4 battery with the BMS built in.This then allows you to use them with any inverter no problems. And many solar chargers can have the settings adjusted to suit adequately the batteries charging needs.

[russ]

Oops!

[Sunking]

As INETDOG has pointed out you can buy a 12,24,48,96,and 144v Life PO4 battery with the BMS built in.This then allows you to use them with any inverter no problems.

While this is true, you cannot justify the expense. LFP batteries have not been proven to last as as long as a good quality FLA battery. When you consider th eLFP option is about 300 to 500R more expensive and only last 1/3 as long, they will not be a serious contender. For now and the foreseeable future LFP will be primarily for the Electric Vehicle market where the cost can be justified since wh/Kg is the most important factor for a EV. wh/Kg for RE applications is not a consideration.

[Mid]

a wee bit off track now

While this is true, you cannot justify the expense. LFP batteries have not been proven to last as as long as a good quality FLA battery. When you consider th eLFP option is about 300 to 500R more expensive and only last 1/3 as long, they will not be a serious contender. For now and the foreseeable future LFP will be primarily for the Electric Vehicle market where the cost can be justified since wh/Kg is the most important factor for a EV. wh/Kg for RE applications is not a consideration.

From New Zealand, I have really enjoyed your discourse so far.
Actually, far in front of the general trade.
I find that here, there is a need for a LiFe battery pack, 100a/h, with a triphase 400v output.

Has anyone ideas on this, please?

[Sunking]

From New Zealand, I have really enjoyed your discourse so far.
Actually, far in front of the general trade.
I find that here, there is a need for a LiFe battery pack, 100a/h, with a triphase 400v output.

Has anyone ideas on this, please?

Yes you had better have a high end BMS system. Just off the top of my head that is around 500 to 1000 cells

[Beanyboy57]

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)?

Panasonic Corporation has announced it will commence mass-producing a compact long-life lithium-ion battery system for home solar power applications this month.
* *
The Panasonic battery system includes a management unit designed to control charge and discharge of the battery. The system can store surplus electricity generated by rooftop solar panels for use when needed, further reducing the dependence on grid supplied power.
**
The lithium-ion battery has a design life time of 5000 cycles, based on an 80% depth of discharge per cycle. This compares very favourably to traditional deep cycle battery technologies such as AGM (Absorbed Glass Mat) and gel; which may only have a serviceable life of 1,500 cycles when discharged to 80%. Sounds like Lithium Iron is gaining popularity and credibility.

[inetdog]

Panasonic Corporation has announced it will commence mass-producing a compact long-life lithium-ion battery system for home solar power applications this month.
* *
The Panasonic battery system includes a management unit designed to control charge and discharge of the battery. The system can store surplus electricity generated by rooftop solar panels for use when needed, further reducing the dependence on grid supplied power.
**
The lithium-ion battery has a design life time of 5000 cycles, based on an 80% depth of discharge per cycle. This compares very favourably to traditional deep cycle battery technologies such as AGM (Absorbed Glass Mat) and gel; which may only have a serviceable life of 1,500 cycles when discharged to 80%. Sounds like Lithium Iron is gaining popularity and credibility.

I am looking forward to seeing the specs and prices! And whether the 5000 cycles is tested or predicted.
And depending on the exact chemistry it uses, I may look for tips on building battery bunkers far from the house.

[russ]

I was just reading that Eestor is at it again - upped the output numbers greatly but no product yet. Looking for more suckers I guess.

[Beanyboy57]

I am looking forward to seeing the specs and prices! And whether the 5000 cycles is tested or predicted.
And depending on the exact chemistry it uses, I may look for tips on building battery bunkers far from the house.

I will follow these developments with interest. I won't need batteries for a few years yet, hopefully by then we will have the energy storage we all dream about!

[choyak]

Hi!

I have an off-grid home with LiFePO4 cells and did this for the *exact* reasoning above - I use it for cooking and all power for my home. I designed the system around the cells, and used a Morningstar MPPT regulator in 'custom' mode.

My pack was US$7000 and came with BMS it is 300Ah 51.2V (nominal 48V)

Any questions?

Awesome, you are off-grid completely. I am hopefully eventually going there, step by step. I now have 180AH of 24v LiFePO4 and a relay to switch between utility and solar. Electric bill is significantly reduced.

No more, I now have 80AH of 48V LiFePo4 and enjoying it. Seems that my simple cell balancing is working well also. I have this

http://www.batteryspace.com/Smart-LED-Balance-Module-for-3.2V-LFP-Cell-with-250mA-Balance-Current-for-L.aspx

[nithin.s.nambiar]

Awesome

Awesome!!!

Mod note - Do not make a one word quote and copy a long paragraph