PSOC definition

[john61ct]

If the average period between 100% Full recharge cycles is 5 or more days on a regular basis, that will significantly impact longevity.

But certainly better than just a few times per month.

Or Never, which is the case for most people who don't calibrate their charge sources to the endAmps spec, likely don't own an ammeter.

99% is not even close to "good enough" even if it's every day.

Everyone who claims their solar gets them to "Full by noon" every day for example.

What's the point of buying properly adjustable gear, if you leave it at factory defaults?

Guaranteed premature infloatulation. . .

[john61ct]

Originally Posted by evm1024

PSOC operation is the likely mode of operation for LiFePO4 in (at least my) boats.

1) Charge to some set point

2) use the bank for some number of days where solar etc is used to up the SOC as it can.

3) if at some point we get too low in SOC due to lack of solar (capacity or sun) then use ICE to charge to the set point (or some larger SOC)

4) at some time when we think that out battery monitor is no longer accurate enough recharge to the set point and start again.

This graph is from a different paper but does show PSOC draw down and the like.

See, now that to me is use of the term completely unnecessarily.

That's just using your LFP bank properly.

Which I know is your point, but like saying solar power output is during daylight hours.

Only needed if contrasting to a source that isn't.

Best stated here as "Don't leave your LFP sitting at Full, only charge when a load will shortly be pulling it back down."

"Sitting at Full as long & often as possible is healthy for lead, but harmful to LFP".

[evm1024]

We agree. It is not the proper use of the term that prompted me to start the thread. But, rather, the improper use.

By knowing the definition we can all use the term correctly where it makes sense.

[Dockhead]

Originally Posted by john61ct

If the average period between 100% Full recharge cycles is 5 or more days on a regular basis, that will significantly impact longevity.

But certainly better than just a few times per month.. . .

You are just guessing at these metrics, right? Why 5 or more days, rather than 10 days? Or two days?



This was actually the subject of the recently closed but popular thread, and after hundreds of posts, I don't think anyone every uncovered any actual objective information.


What you write corresponds with my own guesses, but they are guesses! I am still sad that we couldn't get to the bottom of the question.

[tanglewood]

Originally Posted by evm1024

We agree. It is not the proper use of the term that prompted me to start the thread. But, rather, the improper use.

By knowing the definition we can all use the term correctly where it makes sense.

So I still have no idea what you are saying. Every time someone states something different from what I think you are saying, you agree with them.



What is improper use of the term, in your definition?

[evm1024]

Peace brother

Improper use would be:

my batteries are at 80% PSOC

[tanglewood]

Originally Posted by evm1024

Peace brother

Improper use would be:

my batteries are at 80% PSOC

Seems redundant, but not incorrect.

[sailorboy1]

On my boat PSOC =

Parical state of conscience

[Olddan1943]

Originally Posted by tanglewood

So I still have no idea what you are saying. Every time someone states something different from what I think you are saying, you agree with them.

What is improper use of the term, in your definition?

Yes, I agree. Every time I think I have a handle on it, my brain shorts out again. Someone should really write up the list and acceptable/agree upon definition, for future reference.

[tanglewood]

Here are some examples of what I would consider correct usage.


"My battery is at PSOC". What is it's SOC?" Answer: "It's at 80% SOC"


"I always operate my LFP batteries at PSOC".


"I never leave my LA batteries at PSOC for more that a few days".


"Operating LA batteries at PSOC is bad for them". I'd say this is ambiguous since it's not clear whether the batteries are always operated at PSOC, or if they are operated at PSOC for a limited time and then returned to 100% SOC.

[Stu Jackson]

Originally Posted by Olddan1943

Yes, I agree. Every time I think I have a handle on it, my brain shorts out again. Someone should really write up the list and acceptable/agree upon definition, for future reference.

Didn't Maine Sail just do that?

[StuM]

Originally Posted by tanglewood

Well, it's good you have asked this, because I use the term differently, and will continue to do so.


You are describing PSOC as a behavior, and more particularly as a negative behavior.


I don't use that way at all. I use it literally, to describe a battery's state of charge at an instant in time, as anything less than 100% SOC. It's a state of being, not a behavior, just as 50% SOC is a state, not a behavior. Operating at a PSOC is a behavior involving batteries at a PSOC. Never charging to anything other than a PSOC is a behavior that is detrimental to LA, and favorable to LFP.



So I think it means exactly what you don't think it means. Who ever thought a common language could be so confusing.

I'm with you on this. PSOC is less than 100% SOC . End of story.

[john61ct]

Originally Posted by Dockhead

You are just guessing at these metrics, right? Why 5 or more days, rather than 10 days? Or two days?

I used to think every day was important.

Many more expert than me corrected me and stated at least a few days a week is "good enough".

I am not so unrealistic as to expect serious documentation on the point

Just like the other question of DoD, way too many variables.

And who would fund it?

Industry prefers we replace frequently.

[john61ct]

Originally Posted by evm1024

my batteries are at 80% PSOC

yes good example, that is just silly, since SoC is sufficient.

[john61ct]

Originally Posted by tanglewood

"Operating LA batteries at PSOC is bad for them". I'd say this is ambiguous since it's not clear whether the batteries are always operated at PSOC, or if they are operated at PSOC for a limited time and then returned to 100% SOC.

Exactly why IMO it should only be used wrt that **problem** if not returning to 100%.

"operated at PSOC" is in itself redundant

to make use of a bank it must be discharged, that is inherent in "operate"

Language usage dictates correctness, not pedantic dictionarism.

Search for **every** instance of the term across marine forums from before RR's misuse you will see it refers to the PSOC problem with lead, or lack thereof with LFP and Firefly.

Whew, what a waste of time and energy