End Amps Setup help

[Bob D]

I couldn't find an answer to this through searching:
Classic 150, WBJR, 1849 firmware
Using end amps from the WBJR to end absorb.
Varimax is set to be disabled.
At times, absorb ends prematurely when input from the panels decreases.
For instance, with EA set at 8A, at a point where the absorb cycle was at about 12 amps, it clouded over for 15 minutes, reducing the available charging current to under 8 amps, triggering the transition from absorb to float.
Or at least it seems what it is doing.
It would be nice to be able to set a minimum absorb time or extend the time at EA to something longer to handle such situations.

Or am I missing something.

I did notice something a bit weird with the absorb timer - as I reduce it from 05:35, it rolls over to 18:30 for some reason.
Is this a known glitch or should I be thinking about a re-install.

thanks
Bob

[zoneblue]

With the current firmware and all those back to 1070 or so, the "absorb time" and EA work together.

Which ever comes first triggers float transition. So check your absorb time isnt too low. Otherwise it _shouldnt_ go to float until one of the two occurs. If there is odd things happening my first port of call is a VMM or reset to factory. This should have been done for the last firmware, but if you skipped it first try that. Then keep an eye on it to see if it recurrs at all.

[boB]

EA should only take effect if the charging stage is Absorb...  i.e. the battery voltage must be at or above the
Absorb voltage set point for at least 1 minute.  So, ending earlier than that is a mystery at the moment.

You do have SHUNT selected in the Advanced menu, right ?

The absorb time rolling over from 5 hours to 18 hours is also a mystery as you have VMX disabled.
It might be that you need to do a VMM (Vulcan Mind Meld) to reset some numbers in the Classic.

I don't remember exactly, but it ~may~ be that although VMX is disabled, that minimum absorb time
is set to some weird value  internally ?  VMM would fix that if that is the case.

Is your MNGP version the one from  4-14-2014 ?  (or whatever the most recent one is)   I know that 1849 is 4-21-2014
boB

[Bob D]

I'll try the VMM to see if it fixes the timer issue.
I didn't explain the other issue clearly
EA is set to shunt
Controller goes through bulk, hits 29V and goes into absorb
Current eventually starts to decrease towards the EA of 8A
Before it drops that far, at 12A for instance, the PV input drops due to clouds so that the available charging current drops below 8A and that triggers a transition to float, where it stays
It makes sense from one viewpoint, because the EA target has been reached, although not in the way intended.

[boB]

I'll try the VMM to see if it fixes the timer issue.
I didn't explain the other issue clearly
EA is set to shunt
Controller goes through bulk, hits 29V and goes into absorb
Current eventually starts to decrease towards the EA of 8A
Before it drops that far, at 12A for instance, the PV input drops due to clouds so that the available charging current drops below 8A and that triggers a transition to float, where it stays
It makes sense from one viewpoint, because the EA target has been reached, although not in the way intended.

No, I understood what you wrote, but dropping below 8 amps alone is not what triggers it going to Float.

It needs two (2) conditions at the same time to go to Float.
1)   it has to go below 8 amps, which it does when the clouds go by.

2)   the battery voltage must still be at the absorb voltage.  (the absorb timer is still counting down here)

when your clouds go by, the battery current would have dropped from 12 amps down below 8 amps
but the battery voltage would then be below the absorb set point and the Classic would then be
in BULK MPPT and NOT in absorb at that time so it should not change to float at that point.....

...Not until the battery voltage can stay charging at the absorb set point with less than 8 amps
of charge current being supplied to it.

Does that make sense ?

i.e.  If the batteries are requiring 12 amps to stay at absorb voltage when the clouds
roll by and then the charge current drops below 8 amps, the charge stage will no longer be
in absorb and the two (2) required trigger conditions will not yet exist for the Ending Amps
to trigger a change to Float.

[zoneblue]

Yeah im thinking thats a coincidence, and something else is triggering float.

[boB]

Oh, almost forgot...  Those 2 conditions must exist for at least 60 consecutive seconds.

BUT !  Bugs do exist so anything is possible !

There might be some weird condition I don't know about.

[Bob D]

OK thanks for the input.
I'll look at the local app data to see if there is something else going on.

[Alaska Man]

I had a similar problem with set points. It was my doing. I had the Negative from the Controller terminated on the Battery Negative not the shunt. I'm not sayin this is what you did, but just in case.