While whittling away at the topic of verifying End Amps (http://midniteftp.com/forum/index.php?topic=3779.0) this question popped up... so starting a separate thread.
Absorb is set to 55.2
Float is set to 55.1
End Amps set to "1" (WbJr in installed)
Any good reason the controller would change state from Bulk MPPT to Absorb at .4 volts lower than what is programmed?
check the OFFSET values.
Should have mentioned that I haven't touched the offsets. They are still at 0.
Yes if the batteries are warm and temp compensation is set it would lower the setpoint .
What is temperature compensation value ?
You can go to temp compensation screen and it will show you the temperature compensated setpoint for whatever mode it is in at the time.
Larry
That's another thing I should have mentioned! :> These are LiFePO4 cells. Not using a temp sensor and I have not set a temp compensation. Just checked to be sure.
EDIT: In the last few minutes I rebooted the classic. Both Absorb and Float still lagging by a few 10ths of a volt. Also just raised the absorb absorb and float set point a few 10ths and rebooted. Still the same lag.
I realize that I can compensate for this discrepancy, but I'm still learning about this controller, and interested in seeing how close its tolerances are. My expectations are that it should believe its own readings and stick to them exactly.
Have you re-torqued all the connections recently? removed any connection, etc? Checked for any loose crimped fittings?
How many amps were charging when it changed from Bulk to Absorb ?
Did you put a meter on the battery when it was doing this and see if the voltage was rising rapidly ?
Larry
You might want to try changing the ending amps to 0.0
Where were you measuring the voltage being different ? If on the Classic itself and
your battery temp comp is not used (as I had read), then the EA might be it.
boB
Quote from: Westbranch on July 11, 2017, 09:25:10 PM
Have you re-torqued all the connections recently? removed any connection, etc? Checked for any loose crimped fittings?
The system's only a few days old. One thing I did do around this time is bypass low voltage disconnect. The LVD is a contactor inline with the positive cable between the battery and the inverter. I just placed each crimped cable end on the same terminal of the contact and torqued the bolt down.
I also checked and re-torqued everything. The battery terminals of the LiFePo4 cells were all good for a slight turn with the torque wrench.
Quote from: ClassicCrazy on July 11, 2017, 11:55:19 PM
How many amps were charging when it changed from Bulk to Absorb ?
Did you put a meter on the battery when it was doing this and see if the voltage was rising rapidly ?
Larry
Unknown, and no.
Quote from: boB on July 13, 2017, 02:50:41 AM
You might want to try changing the ending amps to 0.0
Where were you measuring the voltage being different ? If on the Classic itself and
your battery temp comp is not used (as I had read), then the EA might be it.
boB
Thank you for replying.
I was in another building reading from the local application. I caught it shortly after the state had switched to absorb. But I dumped the log later to confirm (attached). It definitely shows bulk to absorb at 54.8, even though the absorb setting on the classic is 55.2.
Set EA to 0.0? Interesting. I was under the impression that setting effected the state change from absorb to float.
In any case, I am just going to watch how things behave over a couple of days and see if this discrepancy continues.
/jim
Some screenshots and log file excerpt to back up what I'm saying.
(EDIT: Just checked yesterday's log (7-13-17) and again bulk transitioned to absorb .4 of a volt early.)
First, I wasn't thinking.... Ending Amps has nothing to do with what you are seeing.
EA only has an effect when the Classic goes from Absorb to Float. Duh... :)
What is the voltage that the Classic regulates to in Absorb ? Does it always stay below your
Absorb set-point voltage ? It should be running withing a tenth or so of a volt of
your absorb voltage setting. It can go slightly below that setting briefly (around 0.3V ?)
but usually only if the sun goes behind a cloud or something like that and is usually
very brief until the Classic can regulate back up to your setting.
What does the Classic display say the battery voltage is at this time ? I would think it
would agree with the Local-App
boB
Quote from: boB on July 13, 2017, 03:49:21 PM
What is the voltage that the Classic regulates to in Absorb ? Does it always stay below your
Absorb set-point voltage ? It should be running withing a tenth or so of a volt of
your absorb voltage setting. It can go slightly below that setting briefly (around 0.3V ?)
but usually only if the sun goes behind a cloud or something like that and is usually
very brief until the Classic can regulate back up to your setting.
Voltage does rise after the change from bulk to absorb. Here's some log excerpts to give an idea what happens:
Absorb setting = 55.2
12:51:58 - 54.8v - state changes from 4 to 3 (bulk to absorb)
12:52:18 - 54.9v
12:54:26 - 55v
12:55:24 - 55.1v (and holds here until next event)
13:19:22 - 55.1v - state changes from 3 to 5 (absorb to float) (Float is indeed set at 55.1)
13:19:24 - 55
voltage then stays at 55, never going higher, and late in the day starts to drop as sun goes down. THIS IS NOT SURPRISING THOUGH, AS THIS TIE OF DAY LOAD CURRENT STARTS TO MATCH INPUT CURRENT
Quote from: boB on July 13, 2017, 03:49:21 PM
What does the Classic display say the battery voltage is at this time ? I would think it
would agree with the Local-App
I will have to verify at the next opportunity. Maybe today, but it's foggy.
/jim
SIDEBAR: I've been experiencing a few other anomalies with this cc but did not want to complicate things. But they are being persistent and maybe worth mentioning:
1) Checking for updates on the local app always fails even though the internet connection appears good. (I'm a network engineer so pretty sure about the static IP settings)
2) If the classic is turned OFF for more than a minute or two the time setting gets lost
3) At least 3 times now the checkbox to use the WBjr for end amps (Tech menu on local app) has become unchecked on its own. This is not due to reboots, because the checkbox stays ticked if the classic is remote booted from the app. I checked before/after
I took delivery on the classic in Dec of 2015. It sat in the sealed box for over a year before being fired up. I see in the manual they are using a 1216 coin battery (really?) so guessing the battery is kaput.
I'll pick up a battery and see what gets remedied with a new one installed. Maybe I'll get lucky and all anomalies will evaporate. ;>
Hi jim,
Regarding the time setting being lost, that 1216 battery, which is in the MNGP on Standard Classics. Did you remove the paper insulator that keeps the battery from being connected before the Classic is commissioned?
You should be able to carefully probe the battery while it is still installed in the MNGP.
Fairly early in the evolution of the Classic, there could be a bit of adhesive residue that could remain on the coin cell contacts that could keep the battery from doing its job when the CC battery breaker was OFF. Also at times some have said that retensioning the battery holder contacts might help
Regarding the LA check boxes, there often is a button toward the right of that checked function that needs to be clicked, to send that data to the Classic (IIRC). Believe that hovering the mouse cursor over this button says something to that effect.
Vic
Vic beat me to it ... about the battery and the adhesive, use some denatured alcohol if you have it, it doesn't add anything to the adhesive...also that second button needs to to be clicked each time any value is changed... you will see, via the app, that some sections have only 1 value to be saved, others have several, to many, to change and save.
hth
Quote from: Vic on July 13, 2017, 05:34:01 PM
Did you remove the paper insulator that keeps the battery from being connected before the Classic is commissioned?
You should be able to carefully probe the battery while it is still installed in the MNGP.
Fairly early in the evolution of the Classic, there could be a bit of adhesive residue that could remain on the coin cell contacts that could keep the battery from doing its job when the CC battery breaker was OFF. Also at times some have said that retensioning the battery holder contacts might help
I had removed the paper. No residue on cell. I don't think its a tension issue because the cell reads .7 volts out of the holder. Good ideas though!
Quote from: Vic on July 13, 2017, 05:34:01 PM
Regarding the LA check boxes, there often is a button toward the right of that checked function that needs to be clicked, to send that data to the Classic (IIRC). Believe that hovering the mouse cursor over this button says something to that effect.
I was sure to click the button. Even went to a different menu... then came back. Box still ticked. Reboot cc via app. Box still ticked.
Quote from: Westbranch on July 13, 2017, 06:36:26 PM
use some denatured alcohol if you have it, it doesn't add anything to the adhesive
Only had isopropyl alcohol. No effect. Battery still reads .7v. Both surfaces look clean and shiny. I think sitting for 1.5 years had its effect. My theory of human created "systems" (burglar alarms, to computer backup systems, to possibly solar systems) is that they require being checked in on periodically. If you don't monitor them they will act like unattended children and go errant on you.
Can't even blame it on those cheap chinese batteries. Midnite spent the bucks on name brand Sony button cells.
Quote from: Westbranch on July 13, 2017, 06:36:26 PM
...also that second button needs to to be clicked each time any value is changed... you will see, via the app, that some sections have only 1 value to be saved, others have several, to many, to change and save.
Thank you. I spotted that. Yeah, it did strike me that there is a save button for discrete groups of settings. And like I was saying, I was careful to leave the menu and come back to it. The tick box had remained checked. Even stayed checked through a reboot. There's another variable somewhere. I am crossing my fingers that the battery stores settings in flash memory other than the time. (?)
i am having that update problem too. every day the status panel gets fogged over and report " error occurred whilst trying to update, please try again"
then i need to click on the window several times to get back
it does this every day without fail
since years
3 midnite classic connected
I disabled updates and it still does it. So no longer suspect of my network. Assuming it's a firmware issue.
What type of internet connections do each of you have?
Ihave sattellite ... and I can no longer connect to MM2 DUE TO LATENCY ISSUES THAT CAN NOT BE Solved
sorry on a tablet,....
Quote from: 5 Minutes 2 Midnite on July 19, 2017, 02:12:16 AM
I disabled updates and it still does it. So no longer suspect of my network. Assuming it's a firmware issue.
Do you think it is possible your BMS is affecting it somehow ? Could you disconnect your BMS and see what happens then ?
Larry
5M2M please include the FW, Net and MNGP versions in your sigline
well, the mm2 works all right for me. it just the update for the status panel. every day at 14.30 aest or there abouts it tries to update. i don't know whether the internet provider blocks it.
when last looking though, i don't think there is a new update on the midnite site anyway. it is just a thing we could do without.
for example windows 10 thinks that 2029 firmware file is a dangerous something. whilst moving it from one hard drive to another it lets you know. and does not want to copy past it.
Australsolarier, is that the local status App you are having issues with? There have been a couple updates of Adobe lately... and I have had issue with getting a good dwnload of that...
yes the local status application. and yes adobe updates without problem, after you close the local app. it is the update of the local application itself.
"AN ERROR OCCURRED WHILST TRYING TO UPDATE - PLEASE TRY AGAIN LATER"
the same happens when trying to update manually. it does this on 7 different computers and laptops.
My laptop too when I start up...... but the local app still works! at least mine does.
Is your LApp NOT working?
I only use the LA for changing settings since I loaded Graham's Android version on my tab...
the application is working alright
the installation is in the shed and i have a designated laptop for all the solar things so i can follow them from inside the house so i do not have to run out into the shed every half hour or so
Local Status App works fine here
0.3.66 version
I updated Adobe Air recently when it prompted me to - no problems.
using Windows 10 .
I tried the Check for updates on the app and it does say Error getting updates
But what I have in here is fine.
I guess if you are having problems I would uninstall everything and start out with fresh copy from Midnite
http://www.midnitesolar.com/firmwareReport.php?firmware_ID=4&firmwareProduct_ID=2&act=edit
Larry
I am seeing some funny behavior on my lithium system.
It went from Bulk to Absorb fast like it usually does - but then it went to Resting 38 unknown instead of float. After awhile it went to Float but wasn't letting any current through even though the Whizbang was reporting -2 system amps . After awhile it slowly started letting some power through and is gradually climbing up current to get the system amps back to zero . Seems like lithium batteries just confuse the brains of Classic - maybe because the Absorb is 56 and float is 54 - too close together for it ? It is letting the net ah go to a negative value and 98% SOC even though the PV is plenty to handle the load .
Larry
Hi Larry,
Believe that the later versions of the Classic FW will make the transition from Absorb to Float, and state that it is in Float for about 90 seconds. If the Classic is providing NO current after that interval, is does go to Resting. IIRC, it does Rest at Reason 38, as the Surface Charge of many/most batteries of reasonable Capacity can require a number of minutes to require Vflt to be reached (even with relatively large system loads).
Believe that one of the motivations for this change, was that under certain conditions, there could be a negative input current, or similar (on Mike's NiFe bank, and several other members, here).
Personally, prefer this change, because, to me, this change makes the Classic more closely match the definition of Float.
Others have said that the Li battery banks are "quite stiff", when this behavior was mentioned.
The LA banks here have a relatively larger voltage difference between Vabs and Vflt, or course ...
FWIW, Vic
Thanks Vic,
Yes now that you explain it I do remember reading about this in the past.
I guess it just takes a bigger load to drag the resting voltage down to let it get all sorted out .
Looking at it now hours later it is in Float and holding the system amps at zero but feeding the loads so it is all good.
I was watching it closer today since I had needed more power. Since the 48v lithium and 24v lead acid share the same combiner box with a split buss bar - I was able to take a string of the PV and switch it over from 24v to 48v system quite easily - all the strings are the same so no problems there. I just wired from bottom input of one breaker string to another breaker on the 48v buss bar. All I need to do is switch breaker to 24v off and breaker to 48v on . Simple ! here is my first attempt at using paint to make illustration
Larry
(//)
Hi Larry,
That is a neat trick with the Combiner.
I will not mention what we do sometimes, in switching things around in the Combiner, HOT ...
Have fun, Vic
Gotta make life interesting eh Vic ?
Well I did this hot - at least the one connection was - but I tried to be very careful.
The Midnite Din rail breakers do not clamp down on stranded 10 gauge very well - kept coming out - at least the type wire I was using - maybe more fine than course . I finally gave up and found a small piece of 8 or 6 gauge to use on it .
I have some of those insulated screwdrivers now too - so used those - makes it a little bit safer.
Larry