Absorb setting is being bypassed

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Re: Absorb setting is being bypassed

Postby JRHill on Sun Mar 17, 2019 10:46 am

raysun wrote:This parameter does not control the Absorb stage. (Only the charging source can terminate the Absorb stage based on its Absorb Timer value.)

True or not?


It is true. But in Battery Monitor Setup > Battery Setup, it is my impression that the "Return Amps" along with "Charged Voltage" and "Time" only influence the result of Days Since Parms Met in the battery softkey menus - a few key presses in to the FlexNet DC screens. So a value in any of these places does not have any affect on battery charging, only a number of days in the calculation.

For me with the way the CC is set for the peak of the summer, the Days Since Parms Met is reached most every day. In the winter with shortened absorbs, it can help explain why the SOC has drifted so far since the summer. Since the charging through the inverter is set more conservatively, the Days Since is never achieved in the winter (mine is at 183.4 days right now).

For my use these Battery Setup questions really have to be correlated with SGs to be meaningful. I.E., when the batteries are full they REALLY are full, as in the SG won't increase any further. That never happens for me in the winter.

So this is how I've used it, anyway. If this works as I think it does, the settings/values will have to change as the batteries age. But a confession: if they are checked & updated at least annually, if you can get the Days Since Parm to reset, you can probably reset your FNDC's SOC by it. See how lazy I am?
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-Well: Grundfos 11-SQF-2 pump, controller & AC switch (CU200, IO101), Tristar 45 Controller, 780w SunTech 195, Trojan golf cart batteries.
-All running since July '11 with various upgrades and workarounds.

Re: Absorb setting is being bypassed

Postby raysun on Sun Mar 17, 2019 11:14 am

I've understood it that way too. My 'True or not?' question is a product of my perverse sense of humor.

SOMETHING is affecting the Absorb charge timers on both my FM80 and FX3048T. 3 hr Absorb time terminates at approx 2:15. Many days a 30 to 70 minute Absorb time.

I know there is a lot of logic behind the Absorb countdown timers. I suspect some of it has changed somehow.

I'm thinking of opening a support ticket so there can be a formal look into the issue.

Before doing so, I'd like to make sure I understand how this particular clock is built - I certainly don't understand what time its telling.
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Re: Absorb setting is being bypassed

Postby SandyP on Mon Mar 18, 2019 1:36 am

JRHill wrote:....I hate to say this but when I added the FNDC to the system I think I may have taken a move backward. I really like the shunts though because they tell me what the real ins-and outs-are despite the overhead.


I get the impression that many users have issues with their FNDCs, and whilst only a guess it seems from forum posts that the use of a generator to charge the batteries somehow "confuses" the FNDC such that it "thinks" the SoC is different to what it really is. This may feed back into the early termination of solar charging?
As I said, just a guess.
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Re: Absorb setting is being bypassed

Postby JRHill on Mon Mar 18, 2019 6:52 pm

SandyP wrote:
JRHill wrote:....I hate to say this but when I added the FNDC to the system I think I may have taken a move backward. I really like the shunts though because they tell me what the real ins-and outs-are despite the overhead.


I get the impression that many users have issues with their FNDCs, and whilst only a guess it seems from forum posts that the use of a generator to charge the batteries somehow "confuses" the FNDC such that it "thinks" the SoC is different to what it really is. This may feed back into the early termination of solar charging?
As I said, just a guess.


I stayed away for a bit to see if anyone else chimed in to your comment but no one did. So I'll say it then, the FNDC, to me, is for someone who is going to really get down to the nuts 'n bolts. It is not for the causal user who thinks the FNDC will give them all the info they need to run and tune their system without understanding. My gosh it has a bunch of other cool features like advanced AGS and tuning for charging, starting/stopping, etc. But ya really need to get into the details. Then is the subject you brought up but don't fully understand 'cause you don't run the FNDC. Sure the SOC drifts and everyone should know that it happens. If you have an FNDC and never check SGs and calibrate the two together then you're really lost. But with or without, ya need to be doing SGs anyway. So we're back to the beginning.

I said I took a major step backward with the FNDC. Its a true statement 'cause I thought it would bring the system more to the intuitive point if I was gone and someone else had to watch over things. It doesn't necessarily do that and in fact adds confusion to the casual user. Instead, use it for what it does well.
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-Well: Grundfos 11-SQF-2 pump, controller & AC switch (CU200, IO101), Tristar 45 Controller, 780w SunTech 195, Trojan golf cart batteries.
-All running since July '11 with various upgrades and workarounds.

Re: Absorb setting is being bypassed

Postby SandyP on Mon Mar 18, 2019 11:59 pm

JRHill wrote:... Sure the SOC drifts and everyone should know that it happens....


Based on the comments on the Outback forums many users are not aware of the SoC drift nor the causes of it. (including inadequate setup params. and the lack of a Peukert's effect parameter in the FNDC etc. etc.)

JRHill wrote:..But with or without, ya need to be doing SGs anyway....


As there are users with VRLA batteries, SGs are not available so I presume they have wanted a simple" method of determining their battery bank SoC. Not much use Outback claiming the FNDC shows you the true SoC when actually it is likely to be incorrect and there is no other clear way of confirming if it is correct or not.
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Mate2
Outback FM60 MPPT (max output lowered to 55amps)
12 x 2V Hoppecke GEL 660 Ah C100 - 24V System
Outback VFX3024 Inverter/Charger
Victron BMV-602s
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Re: Absorb setting is being bypassed

Postby chinezbrun on Wed Mar 20, 2019 2:21 pm

I believe depends of Global Charge Termination Y or N.
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Re: Absorb setting is being bypassed

Postby JRHill on Wed Mar 20, 2019 2:45 pm

chinezbrun wrote:I believe depends of Global Charge Termination Y or N.


You'd have to have more than one CC to really know Y or N.
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Posts: 547
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My RE system: -House: FM 80, VFX 3648, FlexnetDC, FlexWare xformer, Mate 3 / Hub, WattPlot/, 2925w SunTech 195, Trojan L16RE-B Batteries. Backup 1: Honda EU7000is w/2 wire auto start via FM80 aux, backup 2: 11kw Miller Bobcat;
-Well: Grundfos 11-SQF-2 pump, controller & AC switch (CU200, IO101), Tristar 45 Controller, 780w SunTech 195, Trojan golf cart batteries.
-All running since July '11 with various upgrades and workarounds.

Re: Absorb setting is being bypassed

Postby chinezbrun on Thu Mar 21, 2019 12:03 am

JRHill wrote:You'd have to have more than one CC to really know Y or N.

correct, i have two, but still i'm shooting in the dark ...
I'm trying to understand IF Global Charge Termination is influencing the absorption time of CC's, IF Global Charge Termination is influencing different CC's modes ( i.e Charged ). IF, IF, IF...

@ Raysun - if you find some answers from OutBack pls share.
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Re: Absorb setting is being bypassed

Postby raysun on Thu Mar 21, 2019 5:50 am

Sure.
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Hyundai 355 watt panels (6 - 3 strings @ 2 series)

Re: Absorb setting is being bypassed

Postby JeffinthePeace on Fri Mar 22, 2019 3:50 pm

Following this post now too, as my FM80 doesn't seem to be obeying my commands...
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Re: Absorb setting is being bypassed

Postby JRHill on Mon Apr 15, 2019 6:29 pm

Different behaviors continue. Two days ago AGS was Off and the batteries were pulled low but not to low voltage shut down. Around mid afternoon yesterday it was a given that there would be little solar. So I bulked with the bigger gen and moved to the 'lil on for the absorb. Seven hours later I was down to minimum absorb for several hours. I kept restarting the Bulk, and I couldn't get above 92% SOC. Today we had sun and everything charged to 100% as normal.

All the charge voltages were on target. But the SOC was whacked out. How does that happen on what s/b a rolling average? And then back to normal without a reset?!?
JRHill
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Posts: 547
Joined: Thu Feb 17, 2011 12:12 pm
Location: South central WA
My RE system: -House: FM 80, VFX 3648, FlexnetDC, FlexWare xformer, Mate 3 / Hub, WattPlot/, 2925w SunTech 195, Trojan L16RE-B Batteries. Backup 1: Honda EU7000is w/2 wire auto start via FM80 aux, backup 2: 11kw Miller Bobcat;
-Well: Grundfos 11-SQF-2 pump, controller & AC switch (CU200, IO101), Tristar 45 Controller, 780w SunTech 195, Trojan golf cart batteries.
-All running since July '11 with various upgrades and workarounds.

Re: Absorb setting is being bypassed

Postby raysun on Mon Apr 15, 2019 7:00 pm

Jim,

This probably is not what you are seeing, but on occasion, like right now on my system, PV charged the battery to about 45 min of absorb. Then PV harvest decreased (rainstorm), and load increased (wife.) After 3 hrs. @90% range, I kicked on the generator. Voltage rose to absorb, PV harvest could maintain it, inverter charger went idle. PV harvest dropped again, battery voltage dropped below Absorb, but inverter charger did not resume charging. Switching Mode from Auto to On engaged the charger.

As this is being typed, PV harvest has increased with attendant iding of the Inv. charger, and decreased resuming the charger, to maintain the Absorb voltage.

The SOC has ticked up 1%
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My RE system: Flexpower One: FX3048T, (2) FM80, MATE3s, FlexNetDC
Outback 200NC batteries (8 @ 48v)
Outback IBR3 battery enclosure
Suniva 330 watt panels (12 - 6 Strings @ 2 Series)
Hyundai 355 watt panels (6 - 3 strings @ 2 series)

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