LiFePO4 vs Lead Acid a cost analysis for energy storage.

[Sunking]

Only if you use 20% DOD for the Trojan and maybe 80-100% DOD for the LiFePO4 battery which doesn't seem like a fair comparison. You need to use the same DOD for both battery types to wind up with a meaningful comparison.

Oh but I did. That is where you are loosing your argument and showing your ignorance.

In any battery system you size the batteries to have a given about of Autonomy or days to cover your arse for rainy days. In this example was 2.5 days for each battery tech making them equal in every way. The FLA has to be about 15% larger than lithium. Reason is FLA operates from 100% SOC down to 50% or 50% of its capacity is usable for normal operation. In emergency FLA can go down to 0% SOC where Lithium is a brick at 0% SOC. In a Lithium chemistry they operate at 80% SOC down to 20% SOC or 60% of their rated capacity. That means they can be slightly smaller than FLA. In FLA you use no more than 20% per day, and Lithium no more than 25% which is th emodel I used.

So try again because you do not know what you are talking about. What IEEE Board do you sit on and co write for batteries?

[Ian S]

1. Dereck knows an awful lot about batteries,

Well, as I've indicated above, he needs to demonstrate that a lot better and refrain from hurling all the invective. The latter may impress a few and intimidate a few more, but I find it rather pathetic.

[inetdog]

Moderator warning:
Please keep the personal invective to a minimum and concentrate on the facts (or what you consider them to be) if this thread is to remain open.
This applies to all of you.
I would hate to see it close, because useful information is being exchanged in between the personal attacks.

[Ian S]

In FLA you use no more than 20% per day, and Lithium no more than 25% which is th emodel I used.

So you're claiming that using no more than 25% of the LiFePO4 battery will still yield only 4000 cycles of life i.e. the same as the FLA? That seems to be in disagreement with the available cycle life data for the LiFePO4 batteries.

[inetdog]

1: A=B!

2: NO! A=10B!

1: But given X, Y, and Z, how can you possibly say A=10B?

2: Well, given that, actually A=2B, I guess, which proves my point that A is not =B.

1. Well, given the points that your raised, I would have to say that an in depth analysis shows that A=2B, so I was right all along.

It is really entertaining to watch sometimes.

[electrodacus]

In emergency FLA can go down to 0% SOC where Lithium is a brick at 0% SOC.

How is any battery other than a brick at 0% SOC
And I can heat my food at microwave with a 10% SOC LiFePO4 even if is 5x smaller capacity than a Lead Acid.
0% SOC is for an empty but not dead battery most LiFePO4 get their stated capacity at 1C rating at around 3V/cell.

And here is my real battery with 100Ah cells no need to connect multiple A123 20Ah cells.
This battery is available since 2009 so already 5 years in the field used mostly in harsh automotive environment not light off-grid energy storage.
This is not an recommendation or advertising to this battery there are in fact plenty of better LiFePO4 batteries available now in 2014 from plenty of manufacturers.

This battery is currently selling at 620$ same store I got them not going to mention in here and is made of 4 x 100Ah cells with all the necessary connections between cells included.
They are rated >2000 cycles at 80% DOD so not as good quality as the A123 cells but still way over any Lead Acid battery.
Not going to mention again all the other advantages of LiFePO4.

This is a photo with my 24V 100Ah battery used to power my off grid house so you can not say the battery dose not exist The cost of the battery two years ago was the same 1240$ + shipping. Shipping was small since it was purchased from a company in Canada where I also live don't remember exactly around 120$ for shipping.

[inetdog]

Shipping was small since it was purchased from a company in Canada where I also live don't remember exactly around 120$ for shipping.

I have to admit that the shipping costs for Li chemistry is certainly lower per watt hour than either FLA or NiFe.
Just don't try to send either of them by air.

[pleppik]

I would hate to see it close, because useful information is being exchanged in between the personal attacks.

Hear, hear!

I don't have a horse in this race, either, but I'm finding the actual facts to be very helpful.

I'm also surprised by the vehemence of the personal attacks by Sunking. You'd think he suffered some great childhood trauma at the hands of a lithium battery.

[electrodacus]

I have to admit that the shipping costs for Li chemistry is certainly lower per watt hour than either FLA or NiFe.
Just don't try to send either of them by air.

Yes shipping is a bit of a problem people also don't understand the difference between LiFePO4 and LiCOO2 they just hear lithium and think about fire.
But at least 2 years ago I got my 10 pcs A123 from China by air with DHL it was 103$

[Sunking]

Yes shipping is a bit of a problem people also don't understand the difference between LiFePO4 and LiCOO2 they just hear lithium and think about fire.
But at least 2 years ago I got my 10 pcs A123 from China by air with DHL it was 103$

Here is the problem you just admitted. They are not A123 cells. They are cheap knock-off Chi-Com batteries. That is why I called you a liar and and a fraud.

A123 headquarters was headquartered in Walttham Massachusetts and their two manufacturing plants were in Detroit and Livonia Michigan. Now that they are bankrupted and no longer exist A dozen or more Ch-Com companies now make cheap knock-off copies.

The problem I have is there is a chance some poor unsuspecting person will take your advice and try what you are suggesting only to find out the fundamentals are make believe. We have already been through this with you with you home brew Lithium Charge Controller which we all knew was inferior craftsmanship, design, and did not comply with any known industry safety practices or sound engineering practices. It is a fire bomb waiting to explode. I got a real problem with that and you have proven to be incompetent.

So Inetdog, Mike, or Russ go ahead and close the thread, and ban me I do not care. Fact is I really do care about peoples safety and finances. I am ole school and when I see a Snake Oil Salesman I tar and feather them so they learn a lesson and never return. I am done with this thread. If the rest of you want to believe this impostor, all I can say is you have been warned.

[Ian S]

Here is the problem you just admitted. They are not A123 cells. They are cheap knock-off Chi-Com batteries. That is why I called you a liar and and a fraud.

A123 headquarters was headquartered in Walttham Massachusetts and their two manufacturing plants were in Detroit and Livonia Michigan. Now that they are bankrupted and no longer exist

Actually they do still exist as a subsidiary of the largest automotive parts manufacturer in China. But in any event, electrodacus appears to have purchased his batteries two years ago before the company went into bankruptcy and was taken over. Apparently part of the deal was to keep the battery plants open in Michigan. Last month, Wanxiang divested the grid energy business to NEC.

[Mike90250]

......0% SOC is for an empty but not dead battery most LiFePO4 get their stated capacity at 1C rating at around 3V/cell.....

Last I understood, taking a Li battery down to 0, kills it dead. There may be a way to trickle charge it back to life, but that is way beyond this comparison. I'm not that interested in Li cells, and am not deeply following this.

[electrodacus]

Here is the problem you just admitted. They are not A123 cells. They are cheap knock-off Chi-Com batteries. That is why I called you a liar and and a fraud.

A123 headquarters was headquartered in Walttham Massachusetts and their two manufacturing plants were in Detroit and Livonia Michigan. Now that they are bankrupted and no longer exist A dozen or more Ch-Com companies now make cheap knock-off copies.

The problem I have is there is a chance some poor unsuspecting person will take your advice and try what you are suggesting only to find out the fundamentals are make believe. We have already been through this with you with you home brew Lithium Charge Controller which we all knew was inferior craftsmanship, design, and did not comply with any known industry safety practices or sound engineering practices. It is a fire bomb waiting to explode. I got a real problem with that and you have proven to be incompetent.

So Inetdog, Mike, or Russ go ahead and close the thread, and ban me I do not care. Fact is I really do care about peoples safety and finances. I am ole school and when I see a Snake Oil Salesman I tar and feather them so they learn a lesson and never return. I am done with this thread. If the rest of you want to believe this impostor, all I can say is you have been warned.

They were purchased by another company dose not mean that they do not longer exist or produce battery.
When I got the battery 2 years ago they where still A123 Systems.
They where just an example not a recommendation they have a good datasheet and probably not be considered advertising since none will buy 20Ah cell to build an large storage battery for offgrid.
If I have used my GBS batteries it may have been considered advertising even if I do not sell any cells. If I have used as I wanted initial 5 or 6 difrent LiFePO4 and 5 or 6 different Lead Acid it will have confused all people and the difference between them is minimal all LiFePO4 have a cost if real between 15 and 25 cent/kWh and Lead Acid real between 60 and 80 cent /kWh over the life of the battery.


As for the Solar BMS your only valid remark (not sure it was you) was about the 4 x 20A connectors used for 80A. It seems is not allowed as it is but it dose not mean it will not work and I understand why is not allowed.
There are a few solution a simple one use 20A fuses on each wire. Or have a digital sensing circuit for each connector when there is more than 20A on any connector cut the power.
I did not know about the legislation here and after I found out I decided to make the project Open Source and offer this as a dev kit for those that want to make their own modifications on top of my work.
I do admit when I'm wrong and make corrections.
Will you ever do the same?


And since you are a specialist what is your suggestion when off-grid battery storage is needed in cold climate for energy storage.
Legally you need to vent the box. So how do you keep the battery above freezing with temperatures below -30C for months?
And how much energy do you require to do so?

[electrodacus]

Last I understood, taking a Li battery down to 0, kills it dead. There may be a way to trickle charge it back to life, but that is way beyond this comparison. I'm not that interested in Li cells, and am not deeply following this.

0% SOC not the same with 0V not even close in any type of battery.
Depending on type of lithium battery and manufacturer 0% SOC is somewhere between 2.5V and 3V and the battery has no problem to recover from there there is no excessive battery degradation at 0% SOC

And on a side note I see that most people understand that calculation as battery being discharged 100%.
That is used just for the calculation of the total energy stored during the life time of he battery
it will be the same if you do 100% x battery capacity x 800 for trojan or 50% x battery capacity x 1600 cycles based on their own graph.
so the resulting cost will be the same if you use the battery 100% DOD as if you use 50% or 20% DOD
But with 100% in the calculation things look simpler an even so to complex for some.

[pleppik]

Here is the problem you just admitted. They are not A123 cells. They are cheap knock-off Chi-Com batteries.

I'm beginning to suspect that once you strip off the personal invective and name-calling, this is the real issue.

By the published data, it looks like electrodacus's main point is right, in that the LiFePO4 batteries have a lower lifetime cost per kWh than lead acid if you take into account the replacement time of the battery. I have no expertise in this whatsoever, but it seems to be confirmed by multiple other sources online.

But you seem to be arguing that:

• There is unpublished data you have access to because of your expertise that shows differently. If this is true, it would be appreciated if you could share it; or
• The products currently being sold by A123 are not up to the same standards as what they sold before their bankruptcy and sale of the company. Again, if you have access to data which backs this up, it would be great if you could share it; or
• Even though LiFePO4 may seem to be less expensive by the numbers, there are practical considerations which inevitably drive the cost up. If you can be specific about those considerations, that would be helpful.

Since I'm not planning any off-grid PV in the next ten years (and the technology will have changed by then if I do), I don't have any particular interest in the topic other than general curiosity. But curiosity being what it is, I'm really trying to understand what the real arguments are.