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Old 11-09-2018, 17:11   #46
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Re: PSOC definition

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I'm with you on this. PSOC is less than 100% SOC . End of story.
Yes. I agree. It's really that simple.
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Old 11-09-2018, 17:35   #47
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Re: PSOC definition

Why can't we call it "Incomplete Recharge" or something like that?

PSOC appears to be a "term of art", but it is apparently confusing because to the naive outsider the literal definition of that acronym means "less than fully-charged" regardless of duration, or where the battery is in the charge-discharge cycle. Do we really have to settle on an acronym that is so easily misunderstood?

FWIW, I would consider myself a "naive outsider" except that I've been following this and related threads.
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Old 12-09-2018, 00:58   #48
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Re: PSOC definition

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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....
Nobody has mention the word 'equalize' yet! This will burn off the Lead Sulfate crystals - but not if they have hardened too much for too long. One month is too long, maybe two weeks is the absolute maximum before fully charging and then equalizing.

Let me quote from Lifeline batteries:

Justin Godber defined what expected battery life should be, depending on charge regime, assuming daily discharge to 50% and full time voyaging:

Fully charged after each discharge (not feasible on a voyaging boat). Estimated life: 6-9 Years.
Fully recharged at least once a week and equalized once a month. Estimated life: 4-6 Years.
Only recharged to 85% and equalized once a month. Estimated life: 2-4 years.
Only charged to 85% and never equalized. Estimated life: 1 year.
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Old 12-09-2018, 05:13   #49
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Re: PSOC definition

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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.
If some credible expert said it, then it's already more than a guess.

This is a mirror of the maddening sulphation problem.
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Old 12-09-2018, 05:42   #50
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Re: PSOC definition

Equalizing should be seen as preventative maintenance.

The more chronic the PSOC pattern (the less often getting to 100% Full via endAmps)

the more frequent the conditioning should be.

Monthly is a good guideline for when hitting Full at least most cycles.

Note besides Lifeline, equalizing is only for FLA.
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Old 12-09-2018, 07:00   #51
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Re: PSOC definition

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.....Note besides Lifeline, equalizing is only for FLA.
You mean equalising is only for open FLA, not sealed FLA. A very very big difference. Lifeline are one of the few AGMs you can Equalize as well as Fullriver.

There are too many errors in some of your posts.....please be more carefully and check before submitting. Some are just unintelligible on first read to many on these forums.
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Old 12-09-2018, 07:32   #52
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Re: PSOC definition

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Let me also re-state my SoC terminology opinion.

The highest SoC point I ever want my bank to reach in daily use is how I define 100% Full.

That is what I want to see on my BM readout.

Example from leadworld:

We condition / equalize our FLA bank at 15.75V or even higher, maybe monthly, maybe more often.

This is a testing / maintenance protocol, not for daily use.

Just because we **can** go that high, push more AH in at that level, we know it would be harmful to longevity to do so in daily use.

If someone tries to say

you're only charging to 85% by stopping at 14.5V

Does that make sense?

No.

Paying attention to the vendor charge specs is fine if you only want the cycle lifetime they advertise.

Then **your** definition of 100% SoC can be

Hold V at 14.6 until amps trail down to .005C

or whatever.

My 100% is

Hold V at 13.8V until amps trail down to .03C

Likewise, I never let my bank go below 11.9V in daily use.

Thus that is **my** 0% SoC

And every bank from a quality vendor, that has been at or very close to their 20-hour AH rating.

So someone saying

you are using your bank at PSOC

or something nuts like

"20-80%" just makes no sense to me.

And by the way I actually discharge to 60-70% 99% of daily usage, only critical safety nav gear, mostly very low currents, are allowed to get anywhere near 12V.
In this spirit, I've defined 100% full as equivalent to 0% SoC. That means I can get rid of all that charging gear and always have full batteries.

I've also extended this thinking to body weight. I am at 100% of my ideal body weight, so now eat whatever I want and don't bother to exercise.

Perfect.
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Old 12-09-2018, 08:05   #53
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Re: PSOC definition

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Nobody has mention the word 'equalize' yet! This will burn off the Lead Sulfate crystals - but not if they have hardened too much for too long. One month is too long, maybe two weeks is the absolute maximum before fully charging and then equalizing.

Let me quote from Lifeline batteries:

Justin Godber defined what expected battery life should be, depending on charge regime, assuming daily discharge to 50% and full time voyaging:

Fully charged after each discharge (not feasible on a voyaging boat). Estimated life: 6-9 Years.
Fully recharged at least once a week and equalized once a month. Estimated life: 4-6 Years.
Only recharged to 85% and equalized once a month. Estimated life: 2-4 years.
Only charged to 85% and never equalized. Estimated life: 1 year.
This is very interesting. Looks like to me he is stressing the importance of fully recharging after cycling. He didn't differentiate between cycling to 50% DOD and a greater DOD. I infer from that, that the percentage of DOD is not as important as recharging fully. Just my WAG interpretation.
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Old 12-09-2018, 08:13   #54
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Re: PSOC definition

He did state "discharge to 50%". I don't see how we can read anything else into that.
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Old 12-09-2018, 08:27   #55
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Re: PSOC definition

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You mean equalising is only for open FLA, not sealed FLA. A very very big difference.
FLA is by definition open.

SLA is not, VRLA is a subset of that, then AGM.

Where did you get the idea Fullriver get equalized?

Sorry if you have trouble comprehending, I do try to be precise in my writing.
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Old 12-09-2018, 08:31   #56
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Re: PSOC definition

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I infer from that, that the percentage of DOD is not as important as recharging fully. Just my WAG interpretation.
And a completely incorrect one.

It is just a separate issue, that needs to be dealt with separately for clarity.

We just had an extensive thread debunking several myths wrt DoD and longevity, MaineSail gave a great precis of his research & testing there.
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Old 12-09-2018, 09:24   #57
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Re: PSOC definition

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Originally Posted by john61ct View Post
And a completely incorrect one.

It is just a separate issue, that needs to be dealt with separately for clarity.

We just had an extensive thread debunking several myths wrt DoD and longevity, MaineSail gave a great precis of his research & testing there.
No myths were debunked. A lot of opinion was tossed about with no real evidence presented.
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Old 12-09-2018, 09:32   #58
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Re: PSOC definition

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He did state "discharge to 50%". I don't see how we can read anything else into that.
Yes he did and rightly so. When you look at the effects of PSOC and do studies of it, you hold other variable constant. His statements were clearly intended to show how harmful PSOC cycling is on batteries but didn't mention the effects of DOD. But you are correct, reading between the lines can lead to false assumptions but in this case I was assuming he was making a genuine effort to help people increase battery life. It's also important to note that a lot of battery manufacturers publish DOD vs cycle life but I have never seen a PSOC vs cycle life published. I think the reason for that is obvious but does take a little reading between the lines.
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Old 12-09-2018, 09:42   #59
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Re: PSOC definition

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He did state "discharge to 50%". I don't see how we can read anything else into that.
I guess I should have also stated that the DOD vs cycle life charts CLEARLY indicate the amount of energy stored and delivered over the life of the battery is NOT a strong function of DOD. Again, I'm relying on the manufacturers data and that's the best available.
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Old 12-09-2018, 10:47   #60
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Re: PSOC definition

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Originally Posted by john61ct View Post
FLA is by definition open.
This is not correct!

Flooded Lead Acid batteries come in two styles; serviceable and maintenance free that generally have no vents that can be opened so that water can be added. Both are filled with electrolyte and are basically the same.

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SLA is not, VRLA is a subset of that, then AGM.
SLA and VRLA are different acronyms for the same battery, Sealed Lead Acid or Valve Regulated Lead Acid. Gels were originally called SLAs.

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Where did you get the idea Fullriver get equalized?
From their instruction manual.

Maybe you need to start reading a bit more to get your facts right.

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