LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

[john61ct]

Originally Posted by mat jam

How are the Tesla, apple, 737, etc. max customers feeling about their purchases?

None of those use LFP.

[john61ct]

Originally Posted by mat jam

One of the reasons users are choosing LifePO4 is in the belief they can take them down to 20% with no degradation.

Not "no degradation". But the 2000-4000 cycles at that DoD level is a tiny fraction of what you can potentially get from shallower usage.

This "stress" you speak of is not precise.

The EV arena talks about 2C, 5C rates and more for transients.

House bank usage is usually well under 1C, can even max out at .2 or .5C.

And nothing gets "destroyed" by the more stressful usage.

Lifetime is reduced is all. Could still get decades out of them.

All the same factors that go into longevity of **any** chemistry.

Being gullible and buying unrealistic hype is one thing.

You are at the other extreme, unrealistically pessimistic.

[newhaul]

mat
I have said it before but researching the video its even a broader disparity between the cyclic rates in the video they mention 50C charging and discharging.
Those of us using them as house banks are not near that hard on them .
With few exceptions we are not even getting to 1C discharging and likely .5C charging.
That's a major difference and affects the longevity of the battery pack.
One major thing is with the usages described in the video heat is a major factor.
In our usages heat is not a significant factor.

[Delfin]

Originally Posted by mat jam

All I ask is for some hard data or science. I am not interested in getting into a tug of war. Just looking for answers. Post some hard data or sciences and we can lay this topic to rest otherwise we will ASSUME the video stands as is.

Since you have misrepresented, or don't understand what the video is about, it can certainly stand on its own, while you remain clueless with regard to its meaning.

[Delfin]

I really think that when threads like this are taken over by obvious trolls, the best course of action is not too feed the troll. I'm guilty of responding, but as you know, I am of weak character....

God bless him, but let this fellow fry his LA bank as he has said he is doing, and let the rest of us collect and communicate the information we gather from the practical application of this interesting technology. Ignoramuses are not in short supply, and the attempt to educate them, however altruistic the motivation, is a fool's errand.

[nebster]

It amazes me how another know-it-all troll comes on this forum every four to six weeks, almost like clockwork. How are there so many? What's in it for them? Who wades into a monster thread with zillions of posts and just blabbers on and on with hardly a clue, for reply after reply?

It's like moths to a flame.

[rgleason]

Sorry, I guess I responded first. It does keep you guys on your toes! I have a big ugly green troll that I could post if that will help.

[CatNewBee]

Originally Posted by mat jam

All I ask is for some hard data or science. I am not interested in getting into a tug of war. Just looking for answers. Post some hard data or sciences and we can lay this topic to rest otherwise we will ASSUME the video stands as is.

Any hard data will not satisfy you, even if carved in stone you'll claim diamonds are harder and want it made by a higher authority.

So my advise is, buy some cheep cells and make your own tests.

As a happy owner of a DIY LiFeYPO4 house battery, I can make magic things on board FLA owners even can't dream of. It was worth it to swallow the initial costs for us. A reliable and robust power source with no voltage drop is priceless on the water. YMMV.

[mat jam]

[QUOTE=CatNewBee;2854612]Any hard data will not satisfy you, even if carved in stone you'll claim diamonds are harder and want it made by a higher authority.


Do you have any idea why I asked this particular question?

[mat jam]

Originally Posted by Delfin

Since you have misrepresented, or don't understand what the video is about, it can certainly stand on its own, while you remain clueless with regard to its meaning.

Not sure if I should laugh at you or feel sorry for you.

[mat jam]

Originally Posted by john61ct

None of those use LFP.

You need to reread what I wrote.

[mat jam]

I can see clearly that I have done what nobody should ever do - ask for some facts to support claims.

[CatNewBee]

Originally Posted by mat jam

I can see clearly that I have done what nobody should ever do - ask for some facts to support claims.

The facts are, LFP batteries are broadly used in RV, boats and off-grid houses for years, they are tougher than FLA, last longer and perform better. This is proof enough in a practial application. It is very hard and boring to perform a charge / discharge test of 80% capacity at 0.5C ... 1C until they fail.

assume a 0.5C test, it will charge a battery in 2 hours and discharge it in another 2 hours, so one cycle will run 4 hours. Life expectancy is then around 7000 cycles, what leads to a test duration of 28000 hours or 1166 days or 3.2 years. And this will be only a lab test and not real world usage.

A test with a 100Ah 12V battery would burn 8400kWh during the test. 12V x 100Ah x 7000 cycles.

As I said, do the tests yourself.

[senormechanico]

[newhaul]

Originally Posted by mat jam

I can see clearly that I have done what nobody should ever do - ask for some facts to support claims.

well with all that has been posted .