Absorb cycle is too short

[Westbranch]

Is that Absorb timer still counting down in Bulk?

don't know as I have been gyprocking in my 'free' time here at the lake...

It was almost as though the WB jr is working in reverse with the changed settings.

Our bank is just about the same as yours ~900 Ah cap.  and same when we are away, it is fully charged... about a 8 - 10% DoD now we have a fridge 24/7 for the summer....  I am thinking it is like that very long charge yesterday did something to wake up our batteries deepest inner  power reserves and it is like it did NOT DISCHARGE at all last night...?   I've run out of emoticons...

[Westbranch]

trying to post a copy of today's MM graph...
what is your email?

[Westbranch]

well its almost night time here and the battery that suffered 6 hr 55 min  " Float charge" all day is now down to 24.3 V.  I am leaving the Net as well as the fridge on to  night to see where we start tomorrow morning...

sweet dreams .....

[Westbranch]

well we are back at the cabin ...

Got here yesterday pm and caught the last hr of blazing sun!!!  Classic still in Absorb due to morning fog and some scattered clouds... So I lowered the EA on Cl #647 setting it to 2.0 A and 'we shall see what happens tomorrow'!
Full sun forecast for next 2 days...

Well we had full sun when at 13:36 the output current dropped to zero! 

So I went into the LApp and set the EA to zero and Forced Absorb to start again!  So far SO good.

You can see the effect..... Current went higher than it had been and Voltage continued to increase towards the temp adjusted targets.  I almost got to the max V set also....

[Westbranch]

well we are back at the cabin ...

Got here yesterday pm and caught the last hr of blazing sun!!!  Classic still in Absorb due to morning fog and some scattered clouds... So I lowered the EA on Cl #647 setting it to 2.0 A and 'we shall see what happens tomorrow'!
Full sun forecast for next 2 days...

Well we had full sun when at 13:36 the output current dropped to zero! 

So I went into the LApp and set the EA to zero and Forced Absorb to start again!  So far SO good.

You can see the effect..... Current went higher than

[Resthome]

Westbranch..


Your second graph when the graph first drops to floats looks like the battery voltage stayed high. Did you readjust float set point during that time? The top graph shows the voltage dropping when it first when to float which would be correct. Not sure I understand the second graph voltage, although the voltage scale is difficult to read.

Too many CA fires near our lake and it is covered in a haze of smoke so we are staying home until it clears. First it was the 106 temps and now it the smoke.

[Westbranch]

Hi John  ,no  changes made other than setting EA to zero.  Absorb is set to 4:00 hrs.  It is the EA that I had trouble with all along , Ryan mentioned that if the Amps fell below the EA limit for whatever reason like cloud or fridge turning on, the EA rules !

so today is the first time with a 2A EA value and it dropped into Float with full sun and no drop in the AMPs according to the LApp.

I am waiting for Ryan to  jump in with another suggestion.  1 change at a time.

[Vic]

   ...    Ryan mentioned that if the Amps fell below the EA limit for whatever reason like cloud or fridge turning on, the EA rules !   ...

EA rules,  but ONLY when the Absorption voltage is being maintained.  If a cloud reduces the PV power below that which is required to maintain Vabs,  the CC reverts to Bulk MPPT,  and EA should not any longer be used to end charge cycle.

At least,  this is the way that the Classics (and OB MX-60s)  behave,  here.

Vic

[Westbranch]

Hi Vic, that was my understanding too, but what has been occurring, is a couple of trees have been blocking the sun, now that it is lower in the sky it's  for ~ 1hr,  so  that float was entered, it did not return to bulk even when the amperage went back up.  During the summer it worked just fine... Ryan has been emailing me for a while now.... I am suspecting there is something amiss inside that unit (647) 

I will also be doing a FW upgrade with VMM in a couple of days,  after the next batch of clouds and rain pass thru...

Chain saw time soon too! 

[Vic]

Hi Vic, that was my understanding too, but what has been occurring, is a couple of trees have been blocking the sun, now that it is lower in the sky it's  for ~ 1hr,  so  that float was entered, it did not return to bulk even when the amperage went back up.  During the summer it worked just fine... Ryan has been emailing me for a while now.... I am suspecting there is something amiss inside that unit (647) 

OK,  but it you had EA set to a non-zero value,  and the Classic transitioned to Float,  then,  EA has done its job,  and based on the EA value that was set,  by definition,  all battery charging that was deemed to be required,  has been accomplished.

If you wish an additional charge cycle,  ReBulk  is the normal thing to use  if you wish this to be automatic,  or Force Bulk if you are around to manage charging commands.

Had thought that you were at 1849 Cl FW ...  If so,  this FW does have all of the EA stuff working well.

FWIW,    Vic

[Resthome]

I notice that the two controller have a difference of 1 volt for battery voltage. Do the Classics show this on volt difference?

Dosen't look like you are putting in much current for 900AH batteries. Maybe they are fully charged. What kind of SOC do they start the day at?

[Westbranch]

thanks for the probing questions, made me do some more thinking digging...

I sent  several graphs and download files and he was unable to figure out what was happening at that time so one of the other techs suggested the FW update, after lowering the EA setting

Vic, yes FW is the 1839/49 flavour, was thinking of the Rev 2056 Aug 18, 2015.  Believe it is stable now as no comments to the negative seen IIRC...

The issue I have is I want a 4 hr. Absorb, before Float, and that is why I started this thread .

John, yes the 2 banks are1 V apart. 

ADD: I forgot to mention that my sig does not explain about the ability to transfer the 4592 PV output to 647 using a marine battery switch... 

Both banks suffered a bit last winter,  though Cl 4592 suffered a bit less than 647, due to an operator error (did not count on getting snowed out so early) I am happy with the perceived SoC on 647 as it is doing full time duty for the summer and it drops ~ 8 - 10 % each day, and if I don't get the full Absorb the stated SoC is 100% and I can see it in the end of day voltage and early morning voltage, and the effect is cumulative...
4592 just sits in Float right now as I have an Epanel waiting to install and another inverter to buy...

Hope this helps explain where I am right now...  onward and upward

ADD 2: filled in wording to answer Vic's comment that follows...

[Vic]

...   

   ...   Vic, yes FW is the 1839/49
The issue I have is I want a 4 hr. Absorb, before Float, and that is why I .

OK thanks wb ...   But am not certain just what you are saying at the end of that sentence.

But,  if EA is not set to zero,  it will be the factor that ends Absorb,  unless the Absorb time that is  set is satisfied.  This is an OR function.

If you always want a 4-hour Absorb,  then,  would think that you should set EA to zero.

If you run out of PV power before your setting of 4-hours is met,  (and EA is zero),  then the Classic should revert to Bulk MPPT,  and do what it can,  and so on ...  guess I do not see the issue.  This may be shown on the graphic data on the first page (?).   

Just trying to explain the way my CCs operate,   and cannot see the graphs just now.   Have Fun,  Vic

[Halfcrazy]

Vic is correct, to get a 4hr absorb no matter what End Amps MUST be disabled by setting it to 0. If End amps is set to a value and the battery is really full the classic will terminate absorb early based on end amps. It must be in absorb not bulk mppt though or it ignores end amps.

Basically End Amps was designed for battery banks that do not get drained much at all at night and the user does not want to spend unneeded time in absorb as it just boils off water and heats the battery up.

Ryan

[Resthome]

Ryan and Vic are correct if you want to get 4hrs of Absorb set the End Amps to 0.

Of course you going to have to have good sun and full output from your PV to get to Float after Bulk, and 4 Hrs in Absorb as the days get shorter. Of course when it gets colder the PVs do better but the batteries need higher voltages so you need more out of the PV.

Isn't off grid solar fun?