LFP - Decline in charge acceptance rate with battery age

[CatNewBee]

Originally Posted by Albro359

Sounds like BS to me.....100A from solar...seriously ???

Yes, seriously.

- Victron MPPT SmartSolar controller 150/100
- 5 BenQ PM096B00 panels (each 330Wp, 96 cells, Vmp=54.7V , Imp=6.04A; salt water resistant, 5 years warranty 95% of the nominal output + 25 years extended warranty 87% of the nominal output)
https://www.photovoltaik4all.de/medi...M096B00_DE.pdf

Total solar array power 1650Wp

Makes a nice shade over the aft cockpit of our catamaran.

[CatNewBee]

a screenshot from the UI.. 99.9A charging...

[senormechanico]

Originally Posted by sailorboy1

See that's an extra on a "benefit" of no usr to me. The most I ever see is -160 amps running the microwave a few minutes and my T105 440AH handles that.

This fast charging thing looks to me to be another rabbit hole because most boat don't have more than 100 amp charging source.

But you still have the Peukert effect. There's around 15% penalty and taper of the charge toward the end.


I don't, and it needs to be experienced to believe the difference it makes.
Edit:
I should have read forward. CatNewBee said the same thing !

[sailorboy1]

I don't care if it takes 2-3 hours at absorption to get that last bit into my FLA, I have quiet solar for that. Like I already said, my FLA will take the full charge capability I can supply up 90+% charge. That's enough for me on those days that I am running my generator for charging plus "extras".

Not looking to start a fight. I just don't see the benefit of this "fast" charge except on paper for those that don't make a serious charging capacity upgrade.

[newhaul]

Originally Posted by sailorboy1

I don't care if it takes 2-3 hours at absorption to get that last bit into my FLA, I have quiet solar for that. Like I already said, my FLA will take the full charge capability I can supply up 90+% charge. That's enough for me on those days that I am running my generator for charging plus "extras".

Not looking to start a fight. I just don't see the benefit of this "fast" charge except on paper for those that don't make a serious charging capacity upgrade.

true and it is a case by case decision for each cruiser and install. i will have a holding plate refer and watermaker that couple hours extra solar for my case is fully supporting my refer and or my watermaker after the battery is charged. ymmv

[newhaul]

im still waiting on the technical bulliten concerning lfp reduction of acceptance with cycle age.

[a64pilot]

Originally Posted by sailorboy1

Not looking to start a fight. I just don't see the benefit of this "fast" charge except on paper for those that don't make a serious charging capacity upgrade.

It is primarily for people with BIG chargers and big generators and who don’t want Solar, or for whatever reason want to cook with electricity, heat water or some other energy intensive thing.

For us little guys with our little banks, who don’t try to run Airconditioning or cook with electricity, a Honda generator and good Solar takes care of us very well.
Yes, I know we both have Diesel built ins, but we could get by with Honda’s.

[a64pilot]

This doesn’t answer the declining charge acceptance rate.
It primarily is talking about much smaller batteries, but is written in plain English if you will, so non tech those can easily understand.
It would appear that Lithium ages in a very, very similar manner as lead acid does, and it would be logical that acceptance rate along with capacity would decline with age, probably not enough for any of us to ever notice, cause we are unlikely to be hammering in the charge at high rates anyway.
https://batteryuniversity.com/learn/...ased_batteries

[john61ct]

No, 3.5Vpc is plenty high already for longevity.

I use 3.45Vpc for low current rates.

There is no rational reason to get closer to the shoulders, you will still be at or within 5% of rated AH capacity.

[john61ct]

WRT the declining charge acceptance rate.

If it exists it is not relevant.

Ten years and many thousands of cycles later, you're still able to charge at higher that 1C.

Which who does that in the first place?

Let's let this red herring thread die, start another thread to discuss more relevant LFP topics.

.
It primarily is talking about much smaller batteries, but is written in plain English if you will, so non tech those can easily understand.
It would appear that Lithium ages in a very, very similar manner as lead acid does, and it would be logical that acceptance rate along with capacity would decline with age, probably not enough for any of us to ever notice, cause we are unlikely to be hammering in the charge at high rates anyway.
https://batteryuniversity.com/learn/...ased_batteries[/QUOTE]

[john61ct]

I have found many errors and oversimpifications at Battery University.

Useful for noob basic orientation and terminology, but not tech details.

[john61ct]

Ignore

[newhaul]

Originally Posted by john61ct

No, 3.5Vpc is plenty high already for longevity.

I use 3.45Vpc for low current rates.

There is no rational reason to get closer to the shoulders, you will still be at or within 5% of rated AH capacity.

it appears I mis posted the numbers that is for standard lithium ion not Lfp
Therefore I deleted my post of it

[newhaul]

Originally Posted by john61ct

WRT the declining charge acceptance rate.

If it exists it is not relevant.

Ten years and many thousands of cycles later, you're still able to charge at higher that 1C.

Which who does that in the first place?

Let's let this red herring thread die, start another thread to discuss more relevant LFP topics.

.
It primarily is talking about much smaller batteries, but is written in plain English if you will, so non tech those can easily understand.
It would appear that Lithium ages in a very, very similar manner as lead acid does, and it would be logical that acceptance rate along with capacity would decline with age, probably not enough for any of us to ever notice, cause we are unlikely to be hammering in the charge at high rates anyway.
https://batteryuniversity.com/learn/...ased_batteries

[/QUOTE]

the big issue with the paper is it is all over the chemistry spectrum with no continuity so understand that when reading it

[BruceS]

I had LiFePO4 battery bank in my previous houseboat.
Hooked up in 48V nom.
Six monthly 'banging' of each cell in upper limit (to 4.0v) and lower limit (to 2.9v) and they still had the same capacity. At that time I also removed, polished & re-alminoxed each & every connecting link.

(Tested and recorded)