Just how IS Asorb time set?

[Vic]

Have kinna asked this question included with a few others,  and would like to know exactly how to set Asorb times.

Until EA is implemented in the Classics thought that I'd ask this.

So  if the user wants to set an exact Asorb time,  the Min time is set to that value,  the Max time is that min time + one minute,  I think.  Then the Classic always does the min time as long as there is enough input power to maintain the Vasorb ... right ?

Believe that EA when implemented  will need the Min time set to 00,  and the Max time set to something reasonable like two or three hours (depending).  Then EA will dictate the end of Asorb,  unless Max time comes first ...  right?

BUT,  then there is the Asorb time equals the Bulk time for the current charge cycle.  How is this set?  I want to make very certain that I NEVER set this,  and want to see to it that it does not happen accidentally.

On one system here where the PV is fixed at the ideal Winter angle,  Bulk often takes about 4-5 times longer than Asorb.  On another system Asorb takes about 2.5 to 3 times longer than Bulk.

EA is the IDEAL method.  And the second system seems to chronically overcharge the bank ... am down of about 24 minutes of Asorb and still reducing it ... Am resorting to manually turning on the PV in every four days or so and watching for the correct EA value and then forcing Float.    Then turning off the PV upon leaving.

Manually discharged the bank to about 88% SOC yesterday,  set a 2.5 hour Asorb,  turned on the PV,  but Asorb ended early on each CC (both went to Float).  Perhaps a change in the Asorb time does not take effect until the next sunrise?

EDIT: Am running the Nov 9ish (or so) FW if that matters.

Appreciate the help - Thanks,  Vic

[boB]

Have kinna asked this question included with a few others,  and would like to know exactly how to set Asorb times.

Until EA is implemented in the Classics thought that I'd ask this.

So  if the user wants to set an exact Asorb time,  the Min time is set to that value,  the Max time is that min time + one minute,  I think.  Then the Classic always does the min time as long as there is enough input power to maintain the Vasorb ... right ?

Believe that EA when implemented  will need the Min time set to 00,  and the Max time set to something reasonable like two or three hours (depending).  Then EA will dictate the end of Asorb,  unless Max time comes first ...  right?

BUT,  then there is the Asorb time equals the Bulk time for the current charge cycle.  How is this set?  I want to make very certain that I NEVER set this,  and want to see to it that it does not happen accidentally.

On one system here where the PV is fixed at the ideal Winter angle,  Bulk often takes about 4-5 times longer than Asorb.  On another system Asorb takes about 2.5 to 3 times longer than Bulk.

EA is the IDEAL method.  And the second system seems to chronically overcharge the bank ... am down of about 24 minutes of Asorb and still reducing it ... Am resorting to manually turning on the PV in every four days or so and watching for the correct EA value and then forcing Float.    Then turning off the PV upon leaving.

Manually discharged the bank to about 88% SOC yesterday,  set a 2.5 hour Asorb,  turned on the PV,  but Asorb ended early on each CC (both went to Float).  Perhaps a change in the Asorb time does not take effect until the next sunrise?

EDIT: Am running the Nov 9ish (or so) FW if that matters.

Appreciate the help - Thanks,  Vic

EA is definitely the ideal way to end and absorb.

Since bulk does usually take hours to get the battery to absorb, this is why there is the maximum absorb time.
It turns out that around 2 hours is about when you would see the battery current go down to the EA value.
This is why the industry pretty much does it for this long.

The Classic will re-initiate a brand new bulk/absorb once a day.  However you know that you can either force
a new bulk/absorb in the Tweaks menu or set the Re-Bulk voltage to where if the battery voltage drops below
that set point for, like, 90 seconds, the Classic will re-load its bulk absorb timer with the minimum absorb
time and count up to max absorb time from there while in bulk.

You know that you can view that timer right ?  Go to the TIMERs menu in CHARGE and press the soft-right
key and then you can toggle it from HOURS:MINUTES to MIN:SEC with the soft right key  from there.

We'll get that networking going soon I hope and fix any and all problems associated with multiple Classics.
Did you ever try setting one Classic to very short max Absorb time and the other Classic for normal time ?

boB

[plongson]

I'm watching this one too, and not to hyjack, but regarding RE-BULK voltage...I think it defaults to 8 volts. Is the classic looking for an 8 volt drop from some established voltage? (Which would be what?)

[Halfcrazy]

ReBulk defaults to a low value to effectively defeat it. The number you see there is the actual voltage at witch the Classic will initiate a new Bulk charge Cycle.

Ryan

[plongson]

Gotcha!
THNX

[Vic]

Hi boB,

OK,
1. YES,  have set ReBulk somewhere around 50 V -- forget the exact value.  It works well,  and have done Many Force Bulk,  and Float as well works great ( believe that  forcing Bulk on the MX from Float would result in a one or two second Bulk/Asorb cycle and immediately back to Float).  Nice to have this Force Bulk function work so well!

2.  Understand how to set ReBulk voltage and how initiate it,  but this is where my understanding ends ...
you stated,
"in the Tweaks menu or set the Re-Bulk voltage to where if the battery voltage drops below
that set point for, like, 90 seconds, the Classic will re-load its bulk absorb timer with the minimum absorb
time and count up to max absorb time from there while in bulk".

So in ReBulk,  the Classic does the Bulk stage again,  reaches the target Asorb V,  with say a 2.5 hour Min Asorb time,  and a 3.0 hour Max time and the Bulk cycle took 1.0 hours,  how long would this new Asorb take?

3.  AND speaking of the initial charge cycle from sunrise,  with the above timer settings -- Asorb Min= 2.5 Hr,  Max= 3.0 Hr,  and Bulk took 1.0 Hr ...  guess that the Asorb time would be exactly the same as the ReBulk example above ??

4.  The numbers above are an example of what I might manually set in trying to cycle this battery bank down to below 90% SOC,  and initiate a recharge.
Most days this bank is so lightly cycled that about 1.2 Kwh is required to get into Float.  This translates into about 2 hours of Bulk (starts with very low current Bulk,  not long after sunrise),  and 20-30 mins of required Asorb.  But seems that the Asorb is much longer than I expect it to be due to my misunderstanding.

Have set Min time to about 24 mins,  and Max to 25 mins,  hoping to have the Asorb time equal 24 minutes - TOTALLY IRESPECTIVE OF HOW LONG Bulk TOOK.
Is this correct?

5.  NO,  I did not know that I could find Asorb time in the Timers Menu,  until yesterday,  while reviewing old posts,  saw this rererence in the Asorb Time thread  of Jan 18.  Had totally forgotten this if I ever knew it ... Had been looking for it in the Logs menu.

The site with the dual Classics is a ways away,  and has no internet,  and here,  where there IS internet,  there are NO Classics,  so cannot just run out to look at or try something ...

6.  Just now,  do not need both Classics to work together on 90% of the days as the bank is so lightly cycled,  just use one Classic and 1/2 of the PV and that is pleanty.  Do set the second Classic to ON when manually cycling the bank below 90% SOC,  and it always amazes me just how exactly the Classics do Bulk,  usually to within a watt or two of each other,  often delivering about 5 Kw of power.  And the Asorb powers are shared fairly well until later in Asorb.  This is without any Networking twix the two.

The existing approach works OK,  except I think that my Asorb time is quite a bit longer than expected.

7.   How can I make certain that the Asorb time has nothing whatsoever to do with how long Bulk time was   Is it by setting Max Asorb time to be one minute longer than Min time setting?

8.  If one WANTED the Asorb time to equal Bulk time,  HOW would one set this?

In item #2 above,  I do not understand the quote about,  "the Classic will re-load its bulk absorb timer with the minimum absorb
time and count up to max absorb time from there while in bulk".

It appears that there is a Bulk timer that is somehow invloved,  and the Asorb time might be the difference between the Min and Max times,  somehow affected by how long Bulk took.

Use MX-60 here,  still,  on one system,  but have always used EA -- never did understand how the Min/Max/Bulk times interacted on that CC either.  Am just that thick.  Sorry for the War and Peace post,  trying to be clear.  THANKS! Verbose Vic

[boB]

So in ReBulk,  the Classic does the Bulk stage again,  reaches the target Asorb V,  with say a 2.5 hour Min Asorb time,  and a 3.0 hour Max time and the Bulk cycle took 1.0 hours,  how long would this new Asorb take?

In this case, the Classic should spend at least 2.5 hours in Absorb.

2.5 hours is quite long for a minimum absorb I would think BUT we make it tweakable anyway just in case.
The MX60 worked the same way as I remember.

You are understanding this correctly as your #3 shows I think.

8.  "If one WANTED the Asorb time to equal Bulk time,  HOW would one set this?"

     To make BULK time = Absorb time, even in the morning (where you probably really don't want them to be the same because it takes   so long), just make the MAX absorb time as long as it will go  (18 hours ?)  and the minimum time very short.  (a few minutes ?)


#7  "How can I make certain that the Asorb time has nothing whatsoever to do with how long Bulk time was ? ?"

      YES, set them as close to each other as possible.  1 minute difference ~should~ work for this.


"It appears that there is a Bulk timer that is somehow invloved,"

   Yep !    That's how it works.  BULK starts counting up.   How fast it counts up is in seconds right now but this may change in a future revision depending on the size of the battery bank and/or how much PV power is available.

boB  (in Wisconsin at the small wind conference for a couple of days)

[Vic]

OK boB,

Thanks for taking the time while you are on the road.

For the example of very light cycling the bank,  the required Asorb time looks to be about 24 minutes ... was there yesterday,  and the bank looked to be fully charged (perhaps a few points too high on the Pilot cell,  but close enuf).

The 2.5 hour Asorb was the required time for the example of cycling the bank to 88% SOC.  The Bulk time for the recharge from that point took 1 hour and 5 mins IIRC.  The Asorb took 2.5 hours to reach 14 EA (the ideal in my book)

Bulk began at 1 hr past solar noon,  and the Classic pair was initially delivering 95 Amps -- about 5 Kw in ... very impressive boxes.  Thanks

Sorry to be so tedious  One DOES not know what one does not know! (at least not always).  Thanks again,  Vic