LiFePO4 vs Lead Acid a cost analysis for energy storage.

[electrodacus]

Some may already know me even if I'm new on this form.
I had a discussion about my Solar BMS now (Open Source Solar BMS dev board).

I made a youtube video just uploaded today about the cost benefit in using LiFePO4 vs the old and very common Lead Acid.
The video was mostly to show that Lead Acid is a much more expensive option but also talk about the other benefits of LiFePO4.

I was even quite generous with Lead Acid that was why is only 2x more expensive than LiFePO4 if I have included all the other parameters things will have been much worse and in real life I expect Lead Acid to be at least 3 to 5x more expensive over the life time of the battery when compared to LiFePO4.

Of course I'm not the only one to notice this in fact there are people, organizations, and companies that knew this for quite some time over 10 years.

Problem is the DIY community that is a bit slow to change. I hope that this video will alt least make some people read more and get informed about this.

Here is the video

I know some of you have slow and limited access to Internet so I will post here a small jpg of the calculation.




A123 Systems LiFePO4
Trojan L16RE Lead Acid

Then here are some independent laboratory tests done on different LiFePO4 and a VRLA(Valve Regulated Lead Acid) you can see LiFePO4 with just 10% DOD can last for 30000 to 40000 cycles and still retain over 85% of the initial capacity and how the Lead Acid performance is significantly worse around 5 to 10x

LiFePO4 lab test

And here you can read a report presented back in 2007 at International Renewable Energy Storage conference regarding the use of Lithium for energy storage.

Lithium for energy storage

[Mike90250]

1) limited bandwidth = no Utube video here

2) I don't understand your chart at all. it compares a 3.2v 20ah battery (640 wh)
to a 6v 299ah (1800wh) battery not even close to the same thing.

I understand you can safely get 80% discharge and 90% recharge (70% useable) from Li* cells, and you can daily use 30% of the Pb cells. But as it is, the chart as I read it, does not compute.

[electrodacus]

1) limited bandwidth = no Utube video here

2) I don't understand your chart at all. it compares a 3.2v 20ah battery (640 wh)
to a 6v 299ah (1800wh) battery not even close to the same thing.

I understand you can safely get 80% discharge and 90% recharge (70% useable) from Li* cells, and you can daily use 30% of the Pb cells. But as it is, the chart as I read it, does not compute.

I should have made some more explanation in the tread (it is in the video).

2) The size of the battery has noting to do with the price comparison.
You can get larger LiFePO4 or smaller Lead Acid but the price / capacity is about the same and most important the price / energy that can be stored during the lifetime of the battery is the same.

Actually based on the Trojan datasheet there is no advantage if you use 100% of the battery capacity or just first 30% the particular battery L16RE-A had a life cycle of 800 cycles at 100% DOD and 1600 cycles at 50% DOD so there will be no benefit in discharging the battery just 30% vs 80% or even 100% the problem is that it will not last long enough for them to be out of the warranty so they recommend you size the battery to only use 30% thus getting a battery 2x or 3x larger.
There are other reason to get a larger Lead Acid battery like the low capacity and high degradation at high charge and discharge rates.

OK but let me explain the calculations in that table.

You have the LiFePO4 that has a capacity of 64Wh and can be cycled 3000 times at 100% DOD that gets you in a simplified calculation at 64Wh x 3000 = 192kWh of energy that can be sored during the life time of the battery.
On Trojan L16RE-A you have 1794Wh of energy at 10h rate and 800 cycles at 100% DOD so again simple calculation 1794Wh x 800 = 1435kWh during the life of the battery.

Now the cost of the battery is divided by the amount of energy stored in the battery during the life time so
LiFePO4 19$ / 192kWh = 0.099$/kWh
Lead Acid 300$ / 1794kWh = 0.209$/kWh

Now this is not a real number and there are other factors that need to be taken in to account like the battery degradation over time and charge discharge efficient just to name a few but all this will make the Lead Acid look even worse and is to complicated for some people.

[bonaire]

MK Solar, aka Deka, will have new chemistries soon with double the charge cycles compared to prior excellent models. Lithium will have a hard time keeping up in terms of price. A123 themselves are quite good but horribly expensive, historically. And don't even consider the hype around the Tesla gigafactory and their future solution of standby systems. 10 kWh is priced at $15,000 plus electricity integration into a hybrid system. Yes, they will lease them but they also keep incentives and other credits. I doubt they do well.

Also, Lithum systems need somewhat complex battery management balancing systems and voltage tracking to keep them from overcharging. LiFEPO4 not so much but anything else with vent with flame possibility does. You can abuse A123 somewhat. LiFEPO4 large format cells out of China have the best price generally. They will do pretty well in china and selling outside as long as they are of higher quality. Many Chinese buy US made Lead Acid cells, like those from Deka/MK due to higher quality over Chinese brands. Especially for their data center standby systems.

[electrodacus]

MK Solar, aka Deka, will have new chemistries soon with double the charge cycles compared to prior excellent models. Lithium will have a hard time keeping up in terms of price. A123 themselves are quite good but horribly expensive, historically. And don't even consider the hype around the Tesla gigafactory and their future solution of standby systems. 10 kWh is priced at $15,000 plus electricity integration into a hybrid system. Yes, they will lease them but they also keep incentives and other credits. I doubt they do well.

Also, Lithum systems need somewhat complex battery management balancing systems and voltage tracking to keep them from overcharging. LiFEPO4 not so much but anything else with vent with flame possibility does. You can abuse A123 somewhat. LiFEPO4 large format cells out of China have the best price generally. They will do pretty well in china and selling outside as long as they are of higher quality. Many Chinese buy US made Lead Acid cells, like those from Deka/MK due to higher quality over Chinese brands. Especially for their data center standby systems.

What sort of new chemistry ? I do not think there is much to improve on Lead Acid they are around from 1800
Lithium batteries are quite new the first commercial cell was only available in 1991.

I got my A123 20Ah cells form victorpower at 19$/Cell that was exactly two years ago only 10pcs not high volume.
They where small to much trouble so I got the 100Ah GBS cells for my house about the same price /Wh maybe lower life at around 2000 cycles still extremely competitive with any Lead Acid.
The A123 System was acquired by a Chinese car manufacturer when they got bankrupt around 2012.
And just a week or so ago they sold the energy storage division to NEC so they can build large grid power storage for electric companies.

I just build a Solar BMS that will work with most small DIY systems 40A charging 80A discharge easy to modify since is Open Source and the price is similar to a simple Lead Acid solar controller.

For larger systems the price of BMS will be extremely insignificant even if used with existing and expensive car BMS programed for solar use.

In this video comparison I was extremely kind with Lead Acid there is no way in real life Lead Acid is only 2x more expensive is more like 3x to 5x more expensive more one 5x side for solar application do to intermittent nature of solar and wind charging.

You also need an over-sized system at least 30% more solar PV panels to compensate for the charging inefficiency and the way the charging is done (float part that will not utilize the entire power available).

There are so many problems with Lead Acid especially in renewable energy storage I sure I left out quite a few in the video.

[Sunking]

You are full of chit. Lithium will cost you over 4 times as much when compared apples to apples. Sorry not going to let you get away with BS here. Go somewhere else where people are gullible and uninformed. Your crap will not fly here.

[electrodacus]

You are full of chit. Lithium will cost you over 4 times as much when compared apples to apples. Sorry not going to let you get away with BS here. Go somewhere else where people are gullible and uninformed. Your crap will not fly here.

All information is available. See datasheets in the original post.
Where is the BS?

Did you checked my calculations are there any mistakes?
Also did you checked my sources are there any mistakes in there?

There are also some independent laboratory tests showing the performance of LiFePO4 from different manufacturers outperform the Lead Acid buy much more that shown in my calculations.
In fact if I where to take all details in the calculation the Lead Acid will look way, way worse.

I do not sell or advertise any battery manufacturer. Can you say the same?
I do have a Open Source Solar BMS dev board but that is no reason for me to advertise a battery technology (maybe it is but people can check my calculations and sources and make they own informed decision).
I have the necessary knowledge do do this simple calculations and interpret manufacturer spec.
I also live off grid and my own house uses LiFePO4 that I payed with my own money knowing that it will be better for this application.

[Sunking]

I am not going to waste my time with you after your first thread that should have got you banned for advertising and unsafe practices. I am done with you. You are maikin git from batteries that do not exist, assuming 100% DOD which is never done, and not comparing equal sized batteries. 800 cycles on a LR16RE my arse. Use real data like 3000 cycles on a Trojan.

A FLA battery solar system is designed for 5 day autonomy which yields 3 days of usable capacity. To match that you have to use a comparable Lithium. Example if you come up with a 48 volt 500 AH (24 Kwh) FLA battery you have have to use a 48 volt 420 AH lithium (20 Kwh) to compare apples to apples. When you do that Lithium looses big time.

So take your crap elsewhere. You will not get away with it here.

[electrodacus]

I am not going to waste my time with you after your first thread that should have got you banned for advertising and unsafe practices. I am done with you. You are maikin git from batteries that do not exist, assuming 100% DOD which is never done, and not comparing equal sized batteries. 800 cycles on a LR16RE my arse. Use real data like 3000 cycles on a Trojan.

A FLA battery solar system is designed for 5 day autonomy which yields 3 days of usable capacity. To match that you have to use a comparable Lithium. Example if you come up with a 48 volt 500 AH (24 Kwh) FLA battery you have have to use a 48 volt 420 AH lithium (20 Kwh) to compare apples to apples. When you do that Lithium looses big time.

So take your crap elsewhere. You will not get away with it here.

Battery size is not important when you compare battery cost vs energy stored during life time.
800 cycles at 100% DOD is from Trojan datasheet you can also use 1600 cycles at 50% DOD or 2666 cycles at 30% see this graph from Trojan spec you will get the same result 800x1 = 1600x0.5 = 2666x0.3 this are real data.


Of course this number 0.209$/kWh for the life of the battery is just for comparison that L16RE will not last that much in a solar application and the efficiency is not taken in consideration for the sake of simplification.
But as I explained in the video when all details are taken in that calculation Lead Acid will look way worse compared to LiFePO4.

You will do better with a 48V 200Ah LiFePO4 than with a 48V 500Ah Lead Acid
There are many things to consider but you will know that if you will understand how this batteries work.
You should at least understand the Lead Acid that you try to defend here.

Also cost vs capacity is not what you use when you compare batteries that is what I try to explain in this video.
Is important the cost / energy stored during the life of the battery.


That is why you don't buy a 50$ 100W amorphous panel that lasts 7 years but prefer to buy a 100$ 100W monocrystalline panel that lasts 25 years.

[Mike90250]

How can you claim 100% discharge cycles on a battery that is only supposed to be filled up to 90% and drained to 20% ? That's only a 70% cycle, so you can only be pulling out 70AH from a 100AH cell.

What special cells and BMS do you have, that enables the 100% usage? Most come with cautions about the extremes of charge and discharge.

[electrodacus]

How can you claim 100% discharge cycles on a battery that is only supposed to be filled up to 90% and drained to 20% ? That's only a 70% cycle, so you can only be pulling out 70AH from a 100AH cell.

What special cells and BMS do you have, that enables the 100% usage? Most come with cautions about the extremes of charge and discharge.

There are two reasons I used 100% DOD in the calculation.
First is that is simple to calculate and will not confuse people.
Second that is how A123 Systems made the tests on the battery 100% DOD since they wanted to kill the battery sun enough so they do not need to make tests for a very long time. they also charged at 1C and discharged at 2C
If you only charge the LiFePO4 to SOC 90% and discharge down to SOC 20% then the battery will last for much more cycles at least 30% more so around 4000 cycles until it gets to 90% of the original capacity.
If you check the lab test link I provided in original post with the test payed by US department of energy a similar LiFePO4 battery was discharged over 36000 cycles only 10% DOD yes there is no additional zero is 36k cycles at 10% DOD. It took more than a years to do this tests at high charge discharge rates.
The BMS can allow 100% usage but you probably don't want to have an empty battery when you are offgrid.
100% DOD on LiFePO4 is when cell voltage is 2.8V

[Sunking]

You are such a liar and fake. Basically you are a modern day Snake Oil Salesman that needs to be Tarred, Feathered, and Run out of Town.

Lets start with your Cycle Life Graph. You claim it is a Trojan model LR16RE which in fact it is not. Not a honest mistake on your part, but deliberate deception (aka Lie). You are showing an old graph of Trojan Signature line products. LR16RE is the Premium Line. Go to page 7 for the real data which you chose to hide. When you use the correct graph for the recommended 5 day autonomy (3 day real reserve capacity) the LR16RE will yield 4000 cycles. Not 800 that you claim.

Second Deception is you are not comparing Apples to Apples and making false claims. Lithium batteries operate from 80% to 20% DOD which means 60% of rated capacity is used, not 100% as you claim. FLA batteries are used to 50% DOD. To make an honest comparison which you are incapable of, It would take 13 of the A123 AMP20M1HD-A batteries to equal a single Trojan LR16RE-A

Third Deception there is no product made by A123 Systems. They went out of Biz over a year ago. All you can find on the market today is cheap Chi-Com copies which are not near the same quality or last as long.

So when you buy 13 of the Chi-Com copies of the A123 battery will cost you roughly $470. To buy a real Trojan LR16RE-A will cost you roughly $300. Considering the Trojan will last longer, cost less, and you can actually buy Solar Charge Controllers for FLA does not take a genius to figure out you are a SNAKE OIL SALESMAN.

We are not buying your BS. Now get lost.

[electrodacus]

You are such a liar and fake. Basically you are a modern day Snake Oil Salesman that needs to be Tarred, Feathered, and Run out of Town.

Lets start with your Cycle Life Graph. You claim it is a Trojan model LR16RE which in fact it is not. Not a honest mistake on your part, but deliberate deception (aka Lie). You are showing an old graph of Trojan Signature line products. LR16RE is the Premium Line. Go to page 7 for the real data which you chose to hide. When you use the correct graph for the recommended 5 day autonomy (3 day real reserve capacity) the LR16RE will yield 4000 cycles. Not 800 that you claim.

Second Deception is you are not comparing Apples to Apples and making false claims. Lithium batteries operate from 80% to 20% DOD which means 60% of rated capacity is used, not 100% as you claim. FLA batteries are used to 50% DOD. To make an honest comparison which you are incapable of, It would take 13 of the A123 AMP20M1HD-A batteries to equal a single Trojan LR16RE-A

Third Deception there is no product made by A123 Systems. They went out of Biz over a year ago. All you can find on the market today is cheap Chi-Com copies which are not near the same quality or last as long.

So when you buy 13 of the Chi-Com copies of the A123 battery will cost you roughly $470. To buy a real Trojan LR16RE-A will cost you roughly $300. Considering the Trojan will last longer, cost less, and you can actually buy Solar Charge Controllers for FLA does not take a genius to figure out you are a SNAKE OIL SALESMAN.

We are not buying your BS. Now get lost.

First I do not sell any batteries or snake oil whatever that last thing is.

Second. Do you even read what I write in replay to your comments?

Where do I claim is LR16RE ? I precisely state L16RE-A and provide link to spec.
The spec is not old is the new one with the "smart carbon" see the spec I provided in the original post.
Anyway your 16 page document is generic for all RE series and you will see the same graph of cycle life vs DOD.

You probably don't know how to read that graph or you pretend you don't know.

4000 cycles at 20% DOD (Depth Of Discharge) is the same as 800 cycles at 100% DOD and will not make any difference in my calculation.

300$ / 4000 cycles x 0.2 DOD x 1794Wh = 0.209$/kWh
same as
300$ / 800 cycles x 1 DOD x 1794Wh =0.209/kWh

Hope that is not to much math for you.

Same is valid for lithium you can use them from 80% SOC (State Of Charge) to 20% SOC if you want so 60% DOD but you can also use them with no problem from 5% SOC to 95% SOC they test the battery from 0% SOC to 100% SOC see spec that is how it lasts 3000 cycles.

A123 Systems is a real company it went bankrupt in 2012 and been acquired by a Chinese car manufacturer that just last week sold the large scale energy storage division to NEC. They still produce and sell A123 batteries.

There are countless other LiFePO4 manufacturers and all LiFePO4 batteries are great for energy storage quite a different battery from most common LiCoO2 used in laptops and phones.
LiFePO4 is optimized for energy storage where LiCoO2 is optimized for energy density.
Is like the difference between a car battery optimized for starting and a deep cycle battery.

Have you seen the Link in the original post where Sandia National Laboratories made test on different types of LiFePO4 batteries and even compared them with a modern VRLA battery. Do they also sell "snake oil"?

You can see how those LiFePO4 batteries outperform the premium line of Trojan batteries by a factor of 5x to 10x. That is if you can read a graph or make the distinction between SOC and DOD.

And just to be clear I have nothing against Trojan the only reason I use their premium line of battery in this comparison is because it was the best price performance Lead Acid battery out of those that I took in to consideration and it is a popular brand for solar DIY.

[russ]

A123 Systems is a real company it went bankrupt in 2012 and been acquired by a Chinese car manufacturer that just last week sold the large scale energy storage division to NEC. They still produce and sell A123 batteries.

Just like Sunking said? The batteries made today by the new company have nothing to do with earlier - the Chinese group bought a name - made in China says a lot and generally that is not good.

[electrodacus]

Just like Sunking said? The batteries made today by the new company have nothing to do with earlier - the Chinese group bought a name - made in China says a lot and generally that is not good.

This where just batteries used as an example and not a recommendation. The scope of the video and calculations is to show how you should see if a battery is a good value or not.
In general LiFePO4 is a huge improvement over Lead Acid for energy storage.

I will mention again the scope of the video and calculation is to show how you should compare any two batteries when it comes to energy storage.
If you use the battery for UPS type application and do not cycle the battery the calculation will be different and again different for batteries used in electric vehicles where energy density plays an important role.

Most people on this forum use batteries for energy storage and in particular solar energy storage.

So in addition to the lower cost / energy stored during lifetime for LiFePO4 there are other serious advantages.

1) Much higher charge discharge efficiency for LiFePO4 98% at 10h rate and 95% at 2h rate compared to Lead Acid usually well under 70% and as worse as 50% for the last 20% of the charge.
This lower efficiency will require larger solar array to be able to cover those losses on the Lead Acid.
2) Lead Acid will suffer if is just partially charged where LiFePO4 love that.
3) Especially in cold climate Lead Acid batteries will perform bad at low temperature same is true for LiFePO4 but you can have the LiFePO4 inside the house and require no venting. How will you heat the Lead Acid in cold climate ? Since it needs venting and all that heat will go out.
And if used at low temperature available capacity is affected but also the life of the battery.

In almost every aspect the LiFePO4 is a superior battery for solar energy storage.

That is why I use LiFePO4 for my off-grid house.